"Exposing to the right" is over exposed, what now?
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>
> (To enlighten the ignorant: There is zero difference in the amount of noise
> in a 2 minute exposure in low light and a 1/2000s exposure in bright light.
> Photons are photons. If you collect enough to get over the base
> noise-threshold then all those parts of the image that are properly exposed
> will be noise-free in any image, no matter the initial light levels.)
Bzzzzt!
Flat out wrong.
--
lsmft
  |
  |
> "Alan Browne" <alan.browne@FreelunchVideotron.ca> wrote in message
> news:bomdnVV2DovNOVLXnZ2dnUVZ_qWdnZ2d@giganews.com
>> sigh... wrote:
>
> [...]
>
>>> Nothing can be determined from either without the accompanying
>>> photograph.
>>
>> BS. It's clear that the first one was mostly shadow, probably a black
>> card (or underexposed grey card). There may have been a shiny patch,
>> or perhaps a white edge to explain the bumps on the right...
>
> It was a night shot landscape with a blue cast. The moon provide the
> smattering of pixels on the right.
>
>> The second a white card (or over exposed grey card).
>
> It was a snow-laden tree surrounded by snow. The image had a hint of fog.
> All those whites and light grays predictably pushed everything over to the
> right.
>
>> This is so easy to replicate...
>
> True. And it also manages to avoid the point (not you, Floyd).
LOL - zing!
--
Mike Russell - http://www.curvemeister.com
| |
|
Paul Furman wrote:
>
> An interesting related issue I don't understand is how the exposure slider
> works in Lightroom or ACR. I don't know how to duplicate that effect in
> photoshop with curves, levels, etc. Those all do like you describe, moving
> the middle parts of the histogram but there isn't an easy way I can see to
> shift the whole exposure. Hmm, the middle slider on levels comes close but
> still doesn't match the effect.
Image | Adjustments | Exposure... ?
>
> An interesting related issue I don't understand is how the exposure slider
> works in Lightroom or ACR. I don't know how to duplicate that effect in
> photoshop with curves, levels, etc. Those all do like you describe, moving
> the middle parts of the histogram but there isn't an easy way I can see to
> shift the whole exposure. Hmm, the middle slider on levels comes close but
> still doesn't match the effect.
Image | Adjustments | Exposure... ?
| |
|
Porte Rouge wrote:
> Wilba wrote:
>> Porte Rouge wrote:
>>>
>>> I set my exposure to slide the histogram to the right, without clipping
>>> ( when I have time), to capture the most tonal levels . So, now when I
>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>> a good example. The deep colors are washed out. The obvious fix(to me
>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>> is, by reducing exposure in post, am I just ending up in the same place
>>> (histogram to the left) as if I had just ignored the histogram when I
>>> was shooting and set the exposure to properly expose the image using
>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>> tonal values when you reduce exposure in editing.
>>
>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>> the
>> left, so that's a waste of time. To avoid having the deep colours washed
>> out, you need to make use of the full tonal range available in the image.
>> If
>> you have done a good job of exposing to the right, your highlights will
>> be
>> pretty much where they need to be. So then all you need to do is raise
>> the
>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>> tones in the scene end up as dark tones in the image. If you are using
>> the
>> Levels dialog in Photoshop, while you drag the black (or white) point
>> slider, press the Alt key to see which pixels are clipped (or blown).
>>
>> (The following relates to my experience with a Canon 450D. YMMV.)
>
> Aha!
:- ) Was that what you actually wanted to know?
>> There are two parts to exposing to the right - levels in the image and
>> saturation of photosites. Whether you are shooting JPEG or raw, the
>> camera's
>> histogram display shows you the levels in a JPEG produced from the raw
>> data,
>> so the shape of the histogram curve depends on your settings for
>> sharpness,
>> contrast, saturation, colour tone, etc.
And white balance, of course.
>> If you are shooting JPEG, all you can do is avoid piling up the histogram
>> on
>> the right, which prevents gross areas of blown highlights in the image.
>>
>> If you are shooting raw, you can overexpose (beyond the point at which
>> the
>> histogram curve touches the right boundary), by about two steps and still
>> produce an image from the raw without blown highlights. IOW, the headroom
>> between blown highlights in the JPEG and saturation of the photosites is
>> about two steps (in my experience, with the JPEG settings I use).
>>
>> So if you are bracketing for the best possible exposure, go at least two
>> steps over what the histogram tells you is "correct". The maximum
>> possible
>> dynamic range occurs at the point where photosites in the highlights
>> begin
>> to saturate.
>
> What do you mean by steps? Do you mean stops, or steps on the aperture
> or shutter dials?
No, nothing to do with the increments by which the camera's controls change
the exposure - that's arbitrary. An exposure step is a doubling or halving
of the amount of light that reaches the sensor. A stop is a step achieved
via the aperture. Most people also say stop when they mean a step achieved
via the shutter.
> In everyday raw shooting, you can be quite relaxed about having a small
> spike on the right of the histogram - that's actually a good thing.
> Wilba wrote:
>> Porte Rouge wrote:
>>>
>>> I set my exposure to slide the histogram to the right, without clipping
>>> ( when I have time), to capture the most tonal levels . So, now when I
>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>> a good example. The deep colors are washed out. The obvious fix(to me
>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>> is, by reducing exposure in post, am I just ending up in the same place
>>> (histogram to the left) as if I had just ignored the histogram when I
>>> was shooting and set the exposure to properly expose the image using
>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>> tonal values when you reduce exposure in editing.
>>
>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>> the
>> left, so that's a waste of time. To avoid having the deep colours washed
>> out, you need to make use of the full tonal range available in the image.
>> If
>> you have done a good job of exposing to the right, your highlights will
>> be
>> pretty much where they need to be. So then all you need to do is raise
>> the
>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>> tones in the scene end up as dark tones in the image. If you are using
>> the
>> Levels dialog in Photoshop, while you drag the black (or white) point
>> slider, press the Alt key to see which pixels are clipped (or blown).
>>
>> (The following relates to my experience with a Canon 450D. YMMV.)
>
> Aha!
:- ) Was that what you actually wanted to know?
>> There are two parts to exposing to the right - levels in the image and
>> saturation of photosites. Whether you are shooting JPEG or raw, the
>> camera's
>> histogram display shows you the levels in a JPEG produced from the raw
>> data,
>> so the shape of the histogram curve depends on your settings for
>> sharpness,
>> contrast, saturation, colour tone, etc.
And white balance, of course.
>> If you are shooting JPEG, all you can do is avoid piling up the histogram
>> on
>> the right, which prevents gross areas of blown highlights in the image.
>>
>> If you are shooting raw, you can overexpose (beyond the point at which
>> the
>> histogram curve touches the right boundary), by about two steps and still
>> produce an image from the raw without blown highlights. IOW, the headroom
>> between blown highlights in the JPEG and saturation of the photosites is
>> about two steps (in my experience, with the JPEG settings I use).
>>
>> So if you are bracketing for the best possible exposure, go at least two
>> steps over what the histogram tells you is "correct". The maximum
>> possible
>> dynamic range occurs at the point where photosites in the highlights
>> begin
>> to saturate.
>
> What do you mean by steps? Do you mean stops, or steps on the aperture
> or shutter dials?
No, nothing to do with the increments by which the camera's controls change
the exposure - that's arbitrary. An exposure step is a doubling or halving
of the amount of light that reaches the sensor. A stop is a step achieved
via the aperture. Most people also say stop when they mean a step achieved
via the shutter.
> In everyday raw shooting, you can be quite relaxed about having a small
> spike on the right of the histogram - that's actually a good thing.
| |
|
"Wilba" <usenet@CUTTHISimago.com.au> wrote:
>Porte Rouge wrote:
>> Wilba wrote:
>>> Porte Rouge wrote:
>>>>
>>>> I set my exposure to slide the histogram to the right, without clipping
>>>> ( when I have time), to capture the most tonal levels . So, now when I
>>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>>> a good example. The deep colors are washed out. The obvious fix(to me
>>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>>> is, by reducing exposure in post, am I just ending up in the same place
>>>> (histogram to the left) as if I had just ignored the histogram when I
>>>> was shooting and set the exposure to properly expose the image using
>>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>>> tonal values when you reduce exposure in editing.
>>>
>>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>>> the
>>> left, so that's a waste of time. To avoid having the deep colours washed
>>> out, you need to make use of the full tonal range available in the image.
>>> If
>>> you have done a good job of exposing to the right, your highlights will
>>> be
>>> pretty much where they need to be. So then all you need to do is raise
>>> the
>>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>>> tones in the scene end up as dark tones in the image. If you are using
>>> the
>>> Levels dialog in Photoshop, while you drag the black (or white) point
>>> slider, press the Alt key to see which pixels are clipped (or blown).
>>>
>>> (The following relates to my experience with a Canon 450D. YMMV.)
>>
>> Aha!
>
>:- ) Was that what you actually wanted to know?
None of it is correct though. What do you get, for example, if you shoot
a image that is mostly an 18% gray card, against a black background?
If you use ETTR to get the most dynamic range, the gray card will show
up as very close to maximum white in the raw data.
"If you have done a good job of exposing to the right,
your highlights will be pretty much where they need to
be. So then all you need to do is raise the black
point (e.g. using the Levels dialog in Photoshop), so
that the dark ..."
Obviously that is not true. The only time it will be
true is when there actually *are* highlights that are
"pretty much" at pur white. Not all scenes have such
highlights, and therefore not all image data will have
them "pretty much where they need to be".
And that is when you use a raw converter or an editor
for "reducing the exposure in Lightroom just puts your
histogram back to the left.", and it clearly is *not* a
waste of time.
....
>>> So if you are bracketing for the best possible exposure, go at least two
>>> steps over what the histogram tells you is "correct". The maximum
>>> possible
>>> dynamic range occurs at the point where photosites in the highlights
>>> begin
>>> to saturate.
>>
>> What do you mean by steps? Do you mean stops, or steps on the aperture
>> or shutter dials?
>
>No, nothing to do with the increments by which the camera's controls change
>the exposure - that's arbitrary. An exposure step is a doubling or halving
>of the amount of light that reaches the sensor. A stop is a step achieved
>via the aperture. Most people also say stop when they mean a step achieved
>via the shutter.
Yes, they usually say that because in fact it is the
same thing in the context that you have described, it
changes the amount of light reaching the sensor.
And how you can say "nothign to do with the increments
by which the camera's controls change the exposure" and
then describe camera controls changing the
exposure... is amusing.
>> In everyday raw shooting, you can be quite relaxed about having a small
>> spike on the right of the histogram - that's actually a good thing.
It is, assuming you want to clip the highlights.
Otherwise, it's a fatal error, because there is no way
to recover the lost data. On the other hand, if you
back off on exposure just enough to make sure no
highlights are clipped, the loss of 1/2 to 1 stop of
dynamic range probably will mean absolutely nothing
(given that you won't print out anything that can show
more than 5 or 6 fstops and the camera will almost
certainly be recording 8 or more).
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>Porte Rouge wrote:
>> Wilba wrote:
>>> Porte Rouge wrote:
>>>>
>>>> I set my exposure to slide the histogram to the right, without clipping
>>>> ( when I have time), to capture the most tonal levels . So, now when I
>>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>>> a good example. The deep colors are washed out. The obvious fix(to me
>>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>>> is, by reducing exposure in post, am I just ending up in the same place
>>>> (histogram to the left) as if I had just ignored the histogram when I
>>>> was shooting and set the exposure to properly expose the image using
>>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>>> tonal values when you reduce exposure in editing.
>>>
>>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>>> the
>>> left, so that's a waste of time. To avoid having the deep colours washed
>>> out, you need to make use of the full tonal range available in the image.
>>> If
>>> you have done a good job of exposing to the right, your highlights will
>>> be
>>> pretty much where they need to be. So then all you need to do is raise
>>> the
>>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>>> tones in the scene end up as dark tones in the image. If you are using
>>> the
>>> Levels dialog in Photoshop, while you drag the black (or white) point
>>> slider, press the Alt key to see which pixels are clipped (or blown).
>>>
>>> (The following relates to my experience with a Canon 450D. YMMV.)
>>
>> Aha!
>
>:- ) Was that what you actually wanted to know?
None of it is correct though. What do you get, for example, if you shoot
a image that is mostly an 18% gray card, against a black background?
If you use ETTR to get the most dynamic range, the gray card will show
up as very close to maximum white in the raw data.
"If you have done a good job of exposing to the right,
your highlights will be pretty much where they need to
be. So then all you need to do is raise the black
point (e.g. using the Levels dialog in Photoshop), so
that the dark ..."
Obviously that is not true. The only time it will be
true is when there actually *are* highlights that are
"pretty much" at pur white. Not all scenes have such
highlights, and therefore not all image data will have
them "pretty much where they need to be".
And that is when you use a raw converter or an editor
for "reducing the exposure in Lightroom just puts your
histogram back to the left.", and it clearly is *not* a
waste of time.
....
>>> So if you are bracketing for the best possible exposure, go at least two
>>> steps over what the histogram tells you is "correct". The maximum
>>> possible
>>> dynamic range occurs at the point where photosites in the highlights
>>> begin
>>> to saturate.
>>
>> What do you mean by steps? Do you mean stops, or steps on the aperture
>> or shutter dials?
>
>No, nothing to do with the increments by which the camera's controls change
>the exposure - that's arbitrary. An exposure step is a doubling or halving
>of the amount of light that reaches the sensor. A stop is a step achieved
>via the aperture. Most people also say stop when they mean a step achieved
>via the shutter.
Yes, they usually say that because in fact it is the
same thing in the context that you have described, it
changes the amount of light reaching the sensor.
And how you can say "nothign to do with the increments
by which the camera's controls change the exposure" and
then describe camera controls changing the
exposure... is amusing.
>> In everyday raw shooting, you can be quite relaxed about having a small
>> spike on the right of the histogram - that's actually a good thing.
It is, assuming you want to clip the highlights.
Otherwise, it's a fatal error, because there is no way
to recover the lost data. On the other hand, if you
back off on exposure just enough to make sure no
highlights are clipped, the loss of 1/2 to 1 stop of
dynamic range probably will mean absolutely nothing
(given that you won't print out anything that can show
more than 5 or 6 fstops and the camera will almost
certainly be recording 8 or more).
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
"Charles" <charlesschuler@comcast.net> wrote:
>A link for your enjoyment.
>
>http://www.rags-int-inc.com/PhotoTechStuff/ETTR/
Yah gotta admit, that one is great entertainment. There
multiple whole paragraphs where he gets nothing right!
He's also got two links at the bottom of that page, both
of which are equally a riot to read.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>A link for your enjoyment.
>
>http://www.rags-int-inc.com/PhotoTechStuff/ETTR/
Yah gotta admit, that one is great entertainment. There
multiple whole paragraphs where he gets nothing right!
He's also got two links at the bottom of that page, both
of which are equally a riot to read.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
sigh... <sigh@noaddress.com> wrote:
>On Thu, 08 Oct 2009 18:36:37 -0800, floyd@apaflo.com (Floyd L. Davidson)
>wrote:
>>Hmmm... tell me what you make of these two histograms:
>>
>> <http://tinyurl.com/493fyp>
>> <http://tinyurl.com/4l8lle>
>
>Nothing can be determined from either without the accompanying photograph.
Didn't this turn out to be indicative! Not one of the
folks who made so many claims about understanding
histograms can even come up with comments on the article
I'm responding to, much less put their own analysis
forward. DRS at least figured out where the histograms
came from, and was willing to repeat the very simple
characteristics. Alan Browne went a little farther and
did manage to not make any mistakes either. But none of
were anything past the most cursory look, and none
provided any *useful* information.
The article that I am replying to, despite starting with
a grossly incorrect statement (above), which he then
contradicted by giving an analysis, at least was an
effort. There are several mistakes though, but it *is*
a good effort.
>This is why I find histograms so useless. A much better option is a
>viewfinder that displays in real-time the under/over-exposed areas of your
>subject and its composition. Only then will you know what parts of your
>subject you can devote to which range of your sensor.
That is true! But misses the point too, because the
highlight display is derived directly from the
histogram, and anything that makes the histogram more or
less accurate also makes the highlight display more
accurate. Hence this discussion directly relates to how
accurately one can set exposure using the highlight
display to the same degree that it relates to histogram
accuracy.
Setting in camera contrast adjustments will *not* make
the highlight display more or less accurate. It also
will not do that for the histogram either.
Setting White Balance will have a dramatic effect of the
accuracy of both.
Understanding histograms makes that statement rather obvious,
and while DRS and others wanted to get into childish games
of claiming they know histograms, note that none of them
is able to prove it with an easy analysis of a couple of very
neat histograms!
>Since these are merely luminance histograms (not RGB) your first one only
>shows that you have saturated one of the RGB channels in the low-midtones.
It shows no such thing. The vertical scale of the
histogram is almost certainly adjusted with auto-ranging
in the software, but what it means is that the entire
*area* of the image is taken up with those tones. They
are not "saturated".
But there is something interesting about the shape of
that peak! Note that it is a trapezoid, with an almost
squared off top. The indication that provides is that
we probably have a picture of a distant black sky (which
explains the flat top and the angled sides). Almost
nothing else produces the shape. (Think about that for
awhile, and the reason is obvious.)
>Most likely the blue channel. It says absolutely nothing about that being
>the proper exposure for the subject or not. The subject could very well be
>displayed best with that location and shape of histogram.
That is true! Unfortunately you seem to have missed the
other values in the histogram, which do relate to
exposure. (Note too that this is an histogram generated
in post processing, not in the camera.) There is a line
of pixels at the bottom of the display 1 to 3 pixels
high, running up to something about 1 fstop below
maximum white. Those are the pixels to look at to set
exposure. If this were a camera generated histogram one
would want to increase exposure to help reduce noise
back over there on the left side where the large peak
is. But this is actually a editor's histogram, and the
desired white level was not at maximum white, so the
"brightness" was reduced with the effect that all
levels, including noise were reduced.
That is, the camera was exposed to get maximum dynamic
range, and the brightness was reduced in the editor to
retain that dynamic range. If the camera exposure had
been reduced by that amount the noise would not have
gone down when the signal did, and a lower dynamic range
would have been recorded.
That is the advantage of using Expose To The Right.
>The second one it only shows that most of your image was lighter luminance
>values. Not if they were properly distributed or not. It could be a scene
>of a white shell on a sunlit beach with little to no shadows at all, nor
>required. A perfectly fine image, exposed properly. We'll never know,
>because your histogram is not compared to a real image. Reading histograms
>alone is useless information.
Not really! You are of course very correct that it is a
high key image. It is also set to slightly less than
maximum white, just as the other image was. Note also
the "comb" effects showing up on the brighter levels of
the histogram... those pretty much indicate that someone
has used the "contrast" control to stretch the tonal
range for that part of the image.
To show exactly how much one can get *from* an
histogram, lets use an editor to *create* a pair of them
that basically match the two above. The idea is that
this process removes those two specific images from the
information in the histograms. Rather than see that
information in the images, it can be seen as actions
within an editor.
The first one is very simple. Open a blank image,
select the entire image, and add a linear gradient fill
to it. The direction of the fill makes no difference,
but it must completely fill the area of the image. Pick
a pair of colors that are relatively close (it's easier
to use black and white, but it isn't necessary). Try
#202020 and #404040 to get something very close to the
original histogram.
The distance between the two colors will determine the
width of the peak. The absolute values will determine
where the peak is located. If the entire area is
filled, the top will be flat. If a linear gradient is
used, the sides will be straight up and down. To make
the sides lean (for either a triangle or a trapezoid), a
non-linear gradient is necessary. The top can also be
rounded by using the right non-linear gradient. The
exact location and width of the peak can be adjusted
using brightness and contrast. The contrast will,
however, honeycomb the shape if the tonal range is
expanded.
(And note that exactly the same procedure is used to
generate a starting point for either of the two
histograms.)
For the "moon shot", the next step is to select a
relatively small area, say 1/10 the size of the whole
image. A square or rectangle will do (or any other
shape, as only the area is of any significance). If
that area is filled with a single color value a peak at
that value will show up on the histogram. If a gradient
is used, it will be spread out as a line on the floor of
the histogram. The ends of the line will be determined
by the two ending color values of the gradient, and the
height of the line will be determined by the percentage
of image area that it covers. Note that as the
percentage goes up... that first peak will go down.
With only that small area selected, it's width and
position can be manipulated with the brightness and
contrast tools. (If the trapezoid is desired, use a
spherical gradient and draw it diametrically from one
corner to the opposite.)
The second image is only slightly more complex. Use the
same technique to get a single peak, but it should be
roughly 1/2 stop below maximum white. (Rounding the top
depends on what tools a given editor has for non-linear
gradients, so I can't give a universal method to create
that.) To cause the top and right sides of the the peak
to become honey combed, use a rectangular selection that
includes a little more than half the entire image,
selecting all of the brighter half. Use a brightness
adjustment to move it right and left, use a contrast
adjustment to get the honeycomb.
Obviously there *is* a huge volume of information
available in a histogram; and very little of it has
anything at all to do with setting exposure. E.g., the
*contrast* information does *not* help set exposure.
Just because somebody posted it on Luminous Landscape
doesn't make it true. We might note that there are
dozens of web sites saying that ETTR will be more
accurate using a corrected White Balance, but only one
making this false claim about contrast. Also note that
while there are hundreds or thousands of sites
explaining ETTR, there are also a few that claim it's
bogus.
But if one understands histograms, it isn't really hard
to pick out the bogus information.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>On Thu, 08 Oct 2009 18:36:37 -0800, floyd@apaflo.com (Floyd L. Davidson)
>wrote:
>>Hmmm... tell me what you make of these two histograms:
>>
>> <http://tinyurl.com/493fyp>
>> <http://tinyurl.com/4l8lle>
>
>Nothing can be determined from either without the accompanying photograph.
Didn't this turn out to be indicative! Not one of the
folks who made so many claims about understanding
histograms can even come up with comments on the article
I'm responding to, much less put their own analysis
forward. DRS at least figured out where the histograms
came from, and was willing to repeat the very simple
characteristics. Alan Browne went a little farther and
did manage to not make any mistakes either. But none of
were anything past the most cursory look, and none
provided any *useful* information.
The article that I am replying to, despite starting with
a grossly incorrect statement (above), which he then
contradicted by giving an analysis, at least was an
effort. There are several mistakes though, but it *is*
a good effort.
>This is why I find histograms so useless. A much better option is a
>viewfinder that displays in real-time the under/over-exposed areas of your
>subject and its composition. Only then will you know what parts of your
>subject you can devote to which range of your sensor.
That is true! But misses the point too, because the
highlight display is derived directly from the
histogram, and anything that makes the histogram more or
less accurate also makes the highlight display more
accurate. Hence this discussion directly relates to how
accurately one can set exposure using the highlight
display to the same degree that it relates to histogram
accuracy.
Setting in camera contrast adjustments will *not* make
the highlight display more or less accurate. It also
will not do that for the histogram either.
Setting White Balance will have a dramatic effect of the
accuracy of both.
Understanding histograms makes that statement rather obvious,
and while DRS and others wanted to get into childish games
of claiming they know histograms, note that none of them
is able to prove it with an easy analysis of a couple of very
neat histograms!
>Since these are merely luminance histograms (not RGB) your first one only
>shows that you have saturated one of the RGB channels in the low-midtones.
It shows no such thing. The vertical scale of the
histogram is almost certainly adjusted with auto-ranging
in the software, but what it means is that the entire
*area* of the image is taken up with those tones. They
are not "saturated".
But there is something interesting about the shape of
that peak! Note that it is a trapezoid, with an almost
squared off top. The indication that provides is that
we probably have a picture of a distant black sky (which
explains the flat top and the angled sides). Almost
nothing else produces the shape. (Think about that for
awhile, and the reason is obvious.)
>Most likely the blue channel. It says absolutely nothing about that being
>the proper exposure for the subject or not. The subject could very well be
>displayed best with that location and shape of histogram.
That is true! Unfortunately you seem to have missed the
other values in the histogram, which do relate to
exposure. (Note too that this is an histogram generated
in post processing, not in the camera.) There is a line
of pixels at the bottom of the display 1 to 3 pixels
high, running up to something about 1 fstop below
maximum white. Those are the pixels to look at to set
exposure. If this were a camera generated histogram one
would want to increase exposure to help reduce noise
back over there on the left side where the large peak
is. But this is actually a editor's histogram, and the
desired white level was not at maximum white, so the
"brightness" was reduced with the effect that all
levels, including noise were reduced.
That is, the camera was exposed to get maximum dynamic
range, and the brightness was reduced in the editor to
retain that dynamic range. If the camera exposure had
been reduced by that amount the noise would not have
gone down when the signal did, and a lower dynamic range
would have been recorded.
That is the advantage of using Expose To The Right.
>The second one it only shows that most of your image was lighter luminance
>values. Not if they were properly distributed or not. It could be a scene
>of a white shell on a sunlit beach with little to no shadows at all, nor
>required. A perfectly fine image, exposed properly. We'll never know,
>because your histogram is not compared to a real image. Reading histograms
>alone is useless information.
Not really! You are of course very correct that it is a
high key image. It is also set to slightly less than
maximum white, just as the other image was. Note also
the "comb" effects showing up on the brighter levels of
the histogram... those pretty much indicate that someone
has used the "contrast" control to stretch the tonal
range for that part of the image.
To show exactly how much one can get *from* an
histogram, lets use an editor to *create* a pair of them
that basically match the two above. The idea is that
this process removes those two specific images from the
information in the histograms. Rather than see that
information in the images, it can be seen as actions
within an editor.
The first one is very simple. Open a blank image,
select the entire image, and add a linear gradient fill
to it. The direction of the fill makes no difference,
but it must completely fill the area of the image. Pick
a pair of colors that are relatively close (it's easier
to use black and white, but it isn't necessary). Try
#202020 and #404040 to get something very close to the
original histogram.
The distance between the two colors will determine the
width of the peak. The absolute values will determine
where the peak is located. If the entire area is
filled, the top will be flat. If a linear gradient is
used, the sides will be straight up and down. To make
the sides lean (for either a triangle or a trapezoid), a
non-linear gradient is necessary. The top can also be
rounded by using the right non-linear gradient. The
exact location and width of the peak can be adjusted
using brightness and contrast. The contrast will,
however, honeycomb the shape if the tonal range is
expanded.
(And note that exactly the same procedure is used to
generate a starting point for either of the two
histograms.)
For the "moon shot", the next step is to select a
relatively small area, say 1/10 the size of the whole
image. A square or rectangle will do (or any other
shape, as only the area is of any significance). If
that area is filled with a single color value a peak at
that value will show up on the histogram. If a gradient
is used, it will be spread out as a line on the floor of
the histogram. The ends of the line will be determined
by the two ending color values of the gradient, and the
height of the line will be determined by the percentage
of image area that it covers. Note that as the
percentage goes up... that first peak will go down.
With only that small area selected, it's width and
position can be manipulated with the brightness and
contrast tools. (If the trapezoid is desired, use a
spherical gradient and draw it diametrically from one
corner to the opposite.)
The second image is only slightly more complex. Use the
same technique to get a single peak, but it should be
roughly 1/2 stop below maximum white. (Rounding the top
depends on what tools a given editor has for non-linear
gradients, so I can't give a universal method to create
that.) To cause the top and right sides of the the peak
to become honey combed, use a rectangular selection that
includes a little more than half the entire image,
selecting all of the brighter half. Use a brightness
adjustment to move it right and left, use a contrast
adjustment to get the honeycomb.
Obviously there *is* a huge volume of information
available in a histogram; and very little of it has
anything at all to do with setting exposure. E.g., the
*contrast* information does *not* help set exposure.
Just because somebody posted it on Luminous Landscape
doesn't make it true. We might note that there are
dozens of web sites saying that ETTR will be more
accurate using a corrected White Balance, but only one
making this false claim about contrast. Also note that
while there are hundreds or thousands of sites
explaining ETTR, there are also a few that claim it's
bogus.
But if one understands histograms, it isn't really hard
to pick out the bogus information.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
Mike Russell wrote:
> This discussion transcended any technical merit long ago, but here's my two
> cents.
>
> For both Nikon and Canon the histogram is based on converted channel RGB
> values, not raw sensor values.
By experiment I've confirmed this to be the same of Sony's a900 (and I
assume other models). That is to say that the histo changes
characteristic based on changes of contrast or other settings.
I'd prefer, of course, that when I'm shooting in raw only (as I normally
do) that the histo be based solely on the raw data.
The real question is, does it, "really" matter?
Excepting specular reflections and source highlights, as long as the
rest of the histo is inside the post it would not make any difference in
the end - esp. if the histo is broken out by RGB (as it is on my camera
and most recent DSLR's (at least the higher end ones)).
In the end one must use ones metering skills to complement histo
observations, esp. as the former is pre-shot and the later is after the
fact.
For shooting in changing light conditions, the meter trumps the histo.
> This discussion transcended any technical merit long ago, but here's my two
> cents.
>
> For both Nikon and Canon the histogram is based on converted channel RGB
> values, not raw sensor values.
By experiment I've confirmed this to be the same of Sony's a900 (and I
assume other models). That is to say that the histo changes
characteristic based on changes of contrast or other settings.
I'd prefer, of course, that when I'm shooting in raw only (as I normally
do) that the histo be based solely on the raw data.
The real question is, does it, "really" matter?
Excepting specular reflections and source highlights, as long as the
rest of the histo is inside the post it would not make any difference in
the end - esp. if the histo is broken out by RGB (as it is on my camera
and most recent DSLR's (at least the higher end ones)).
In the end one must use ones metering skills to complement histo
observations, esp. as the former is pre-shot and the later is after the
fact.
For shooting in changing light conditions, the meter trumps the histo.
| |
|
Wilba wrote:
> Porte Rouge wrote:
>> Wilba wrote:
>>> Porte Rouge wrote:
>>>> I set my exposure to slide the histogram to the right, without clipping
>>>> ( when I have time), to capture the most tonal levels . So, now when I
>>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>>> a good example. The deep colors are washed out. The obvious fix(to me
>>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>>> is, by reducing exposure in post, am I just ending up in the same place
>>>> (histogram to the left) as if I had just ignored the histogram when I
>>>> was shooting and set the exposure to properly expose the image using
>>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>>> tonal values when you reduce exposure in editing.
>>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>>> the
>>> left, so that's a waste of time. To avoid having the deep colours washed
>>> out, you need to make use of the full tonal range available in the image.
>>> If
>>> you have done a good job of exposing to the right, your highlights will
>>> be
>>> pretty much where they need to be. So then all you need to do is raise
>>> the
>>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>>> tones in the scene end up as dark tones in the image. If you are using
>>> the
>>> Levels dialog in Photoshop, while you drag the black (or white) point
>>> slider, press the Alt key to see which pixels are clipped (or blown).
>>>
>>> (The following relates to my experience with a Canon 450D. YMMV.)
>> Aha!
>
> :- ) Was that what you actually wanted to know?
>
>>> There are two parts to exposing to the right - levels in the image and
>>> saturation of photosites. Whether you are shooting JPEG or raw, the
>>> camera's
>>> histogram display shows you the levels in a JPEG produced from the raw
>>> data,
>>> so the shape of the histogram curve depends on your settings for
>>> sharpness,
>>> contrast, saturation, colour tone, etc.
>
> And white balance, of course.
>
>>> If you are shooting JPEG, all you can do is avoid piling up the histogram
>>> on
>>> the right, which prevents gross areas of blown highlights in the image.
>>>
>>> If you are shooting raw, you can overexpose (beyond the point at which
>>> the
>>> histogram curve touches the right boundary), by about two steps and still
>>> produce an image from the raw without blown highlights. IOW, the headroom
>>> between blown highlights in the JPEG and saturation of the photosites is
>>> about two steps (in my experience, with the JPEG settings I use).
>>>
>>> So if you are bracketing for the best possible exposure, go at least two
>>> steps over what the histogram tells you is "correct". The maximum
>>> possible
>>> dynamic range occurs at the point where photosites in the highlights
>>> begin
>>> to saturate.
>> What do you mean by steps? Do you mean stops, or steps on the aperture
>> or shutter dials?
>
> No, nothing to do with the increments by which the camera's controls change
> the exposure - that's arbitrary. An exposure step is a doubling or halving
> of the amount of light that reaches the sensor. A stop is a step achieved
> via the aperture. Most people also say stop when they mean a step achieved
> via the shutter.
The original meaning of a stop comes form a"stop" plate with varied
sized holes in it. Today that would be the "f-stop".
Otherwise a stop is a stop no matter how it is achieved. This is
inherent in reciprocity.
Whether aperture, shutter speed, filters, light levels (control of flash
or constant lighting by any means) it's a "stop" (or fraction thereof).
> Porte Rouge wrote:
>> Wilba wrote:
>>> Porte Rouge wrote:
>>>> I set my exposure to slide the histogram to the right, without clipping
>>>> ( when I have time), to capture the most tonal levels . So, now when I
>>>> am editing the photos they are over exposed(not clipped). A sunrise is
>>>> a good example. The deep colors are washed out. The obvious fix(to me
>>>> anyway) in Lightroom or CS4 is to reduce the exposure. Now my question
>>>> is, by reducing exposure in post, am I just ending up in the same place
>>>> (histogram to the left) as if I had just ignored the histogram when I
>>>> was shooting and set the exposure to properly expose the image using
>>>> my light meter? I guess in short I am asking if Lightroom or CS4 loses
>>>> tonal values when you reduce exposure in editing.
>>> Yes, reducing the exposure in Lightroom just puts your histogram back to
>>> the
>>> left, so that's a waste of time. To avoid having the deep colours washed
>>> out, you need to make use of the full tonal range available in the image.
>>> If
>>> you have done a good job of exposing to the right, your highlights will
>>> be
>>> pretty much where they need to be. So then all you need to do is raise
>>> the
>>> black point (e.g. using the Levels dialog in Photoshop), so that the dark
>>> tones in the scene end up as dark tones in the image. If you are using
>>> the
>>> Levels dialog in Photoshop, while you drag the black (or white) point
>>> slider, press the Alt key to see which pixels are clipped (or blown).
>>>
>>> (The following relates to my experience with a Canon 450D. YMMV.)
>> Aha!
>
> :- ) Was that what you actually wanted to know?
>
>>> There are two parts to exposing to the right - levels in the image and
>>> saturation of photosites. Whether you are shooting JPEG or raw, the
>>> camera's
>>> histogram display shows you the levels in a JPEG produced from the raw
>>> data,
>>> so the shape of the histogram curve depends on your settings for
>>> sharpness,
>>> contrast, saturation, colour tone, etc.
>
> And white balance, of course.
>
>>> If you are shooting JPEG, all you can do is avoid piling up the histogram
>>> on
>>> the right, which prevents gross areas of blown highlights in the image.
>>>
>>> If you are shooting raw, you can overexpose (beyond the point at which
>>> the
>>> histogram curve touches the right boundary), by about two steps and still
>>> produce an image from the raw without blown highlights. IOW, the headroom
>>> between blown highlights in the JPEG and saturation of the photosites is
>>> about two steps (in my experience, with the JPEG settings I use).
>>>
>>> So if you are bracketing for the best possible exposure, go at least two
>>> steps over what the histogram tells you is "correct". The maximum
>>> possible
>>> dynamic range occurs at the point where photosites in the highlights
>>> begin
>>> to saturate.
>> What do you mean by steps? Do you mean stops, or steps on the aperture
>> or shutter dials?
>
> No, nothing to do with the increments by which the camera's controls change
> the exposure - that's arbitrary. An exposure step is a doubling or halving
> of the amount of light that reaches the sensor. A stop is a step achieved
> via the aperture. Most people also say stop when they mean a step achieved
> via the shutter.
The original meaning of a stop comes form a"stop" plate with varied
sized holes in it. Today that would be the "f-stop".
Otherwise a stop is a stop no matter how it is achieved. This is
inherent in reciprocity.
Whether aperture, shutter speed, filters, light levels (control of flash
or constant lighting by any means) it's a "stop" (or fraction thereof).
| |
|
Charles wrote:
> A link for your enjoyment.
>
> http://www.rags-int-inc.com/PhotoTechStuff/ETTR/
>
>
While forcefully written and mostly (which means more than 50%) right,
it contains vague or erroneous claims of source information.
For example: Claim: "The photographic design point is, has been, and
will continue to be based on the middle gray tone. This is the basis
of the sunny daylight f/16 rule. It is the reference point for all
exposure metering systems. It is also ingrained into the CIE color
matching functions and all color order systems. "
CIE 1931 makes no reference to sunny-16 nor to grey as control point
(other than to say that grey is just another version of white).
> A link for your enjoyment.
>
> http://www.rags-int-inc.com/PhotoTechStuff/ETTR/
>
>
While forcefully written and mostly (which means more than 50%) right,
it contains vague or erroneous claims of source information.
For example: Claim: "The photographic design point is, has been, and
will continue to be based on the middle gray tone. This is the basis
of the sunny daylight f/16 rule. It is the reference point for all
exposure metering systems. It is also ingrained into the CIE color
matching functions and all color order systems. "
CIE 1931 makes no reference to sunny-16 nor to grey as control point
(other than to say that grey is just another version of white).
| |
|
Paul Furman <paul-@-edgehill.net> wrote in
news:hajq5b$nt5$1@news.eternal-september.org:
> OK, this makes sense, the posterizing issue is not really visible in
> any sort of normal exposure.
It shouldn't be visible in any kind of exposure. My comments about the
limit of the value of RAW bit depth or the number of RAW levels is based
on torturous tests!
> What about Floyd's comment below that the
> noise level remains the same but exposing to the right increases the
> signal so that overwhelms the noise?
The read noise (including any dark current) stays the same, in an
absolute sense. In a relative sense, it changes. For shot noise, it
changes in both an absolute sense *and* a relative sense.
> That seems to tie the two
> together in a comprehensible way. The LL link just makes a lot of
> sense, it can't be complete BS.
> http://www.luminous-landscape.com/tutorials/expose-right.sht ml
Well, the reasons given for the benefit are not correct. You could take
one shot with normal exposure, and one with +1 EC, now using the top RAW
stop, and the benefit would still be there if you quantized the top stop
to 300 levels, instead of ~8000. According to my calculations and
emulations, no current DSLR needs more than 300 levels for the top stop
(some older models with few, large pixels may need about 325).
news:hajq5b$nt5$1@news.eternal-september.org:
> OK, this makes sense, the posterizing issue is not really visible in
> any sort of normal exposure.
It shouldn't be visible in any kind of exposure. My comments about the
limit of the value of RAW bit depth or the number of RAW levels is based
on torturous tests!
> What about Floyd's comment below that the
> noise level remains the same but exposing to the right increases the
> signal so that overwhelms the noise?
The read noise (including any dark current) stays the same, in an
absolute sense. In a relative sense, it changes. For shot noise, it
changes in both an absolute sense *and* a relative sense.
> That seems to tie the two
> together in a comprehensible way. The LL link just makes a lot of
> sense, it can't be complete BS.
> http://www.luminous-landscape.com/tutorials/expose-right.sht ml
Well, the reasons given for the benefit are not correct. You could take
one shot with normal exposure, and one with +1 EC, now using the top RAW
stop, and the benefit would still be there if you quantized the top stop
to 300 levels, instead of ~8000. According to my calculations and
emulations, no current DSLR needs more than 300 levels for the top stop
(some older models with few, large pixels may need about 325).
| |
|
Mike Russell wrote:
> On Mon, 05 Oct 2009 15:23:57 -0800, Floyd L. Davidson wrote:
>
> [re film's "expose for shadows", digital's "expose for the highlights"]
>> Actually, since film is a negative, the two are in fact
>> actually the same. Expose for the brightest range of the
>> *recording* *mechanism*.
>>
>> That just happens to be the dark areas of a scene with
>> film (where the negative is clear) and the bright areas
>> of a scene with an electronic sensor (the highest
>> voltage output).
>
> No - both refer to areas of the scene. The full rule of thumb for film is
> "Expose for the shadows. Develop for the highlights". Exposing for the
> shadows establishes the area of minimum negative density, and development
> has a much greater effect on the highlights than the shadows.
As I've mentioned before in this thread, digital sensors resemble slide
film, not negative.
For slide film, the "rule" has always been to expose for the highlights,
not the shadows. Development (except for push/pull) is cast more or
less in concrete.
> On Mon, 05 Oct 2009 15:23:57 -0800, Floyd L. Davidson wrote:
>
> [re film's "expose for shadows", digital's "expose for the highlights"]
>> Actually, since film is a negative, the two are in fact
>> actually the same. Expose for the brightest range of the
>> *recording* *mechanism*.
>>
>> That just happens to be the dark areas of a scene with
>> film (where the negative is clear) and the bright areas
>> of a scene with an electronic sensor (the highest
>> voltage output).
>
> No - both refer to areas of the scene. The full rule of thumb for film is
> "Expose for the shadows. Develop for the highlights". Exposing for the
> shadows establishes the area of minimum negative density, and development
> has a much greater effect on the highlights than the shadows.
As I've mentioned before in this thread, digital sensors resemble slide
film, not negative.
For slide film, the "rule" has always been to expose for the highlights,
not the shadows. Development (except for push/pull) is cast more or
less in concrete.
| |
|
Wilba wrote:
> Paul Furman wrote:
>
>> An interesting related issue I don't understand is how the exposure slider
>> works in Lightroom or ACR. I don't know how to duplicate that effect in
>> photoshop with curves, levels, etc. Those all do like you describe, moving
>> the middle parts of the histogram but there isn't an easy way I can see to
>> shift the whole exposure. Hmm, the middle slider on levels comes close but
>> still doesn't match the effect.
>
> Image | Adjustments | Exposure... ?
Hmph, CS1 doesn't have that.
--
Paul Furman
www.edgehill.net
www.baynatives.com
all google groups messages filtered due to spam
> Paul Furman wrote:
>
>> An interesting related issue I don't understand is how the exposure slider
>> works in Lightroom or ACR. I don't know how to duplicate that effect in
>> photoshop with curves, levels, etc. Those all do like you describe, moving
>> the middle parts of the histogram but there isn't an easy way I can see to
>> shift the whole exposure. Hmm, the middle slider on levels comes close but
>> still doesn't match the effect.
>
> Image | Adjustments | Exposure... ?
Hmph, CS1 doesn't have that.
--
Paul Furman
www.edgehill.net
www.baynatives.com
all google groups messages filtered due to spam
| |
|
On Oct 10, 1:57 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
> And how you can say "nothign to do with the increments
> by which the camera's controls change the exposure" and
> then describe camera controls changing the
> exposure... is amusing.
I think he meant the increments on the controls are arbitrary(1/3,
1/2, or 1 stop for each click on the dials.
> And how you can say "nothign to do with the increments
> by which the camera's controls change the exposure" and
> then describe camera controls changing the
> exposure... is amusing.
I think he meant the increments on the controls are arbitrary(1/3,
1/2, or 1 stop for each click on the dials.
| |
|
Porte Rouge <porterougeman@gmail.com> wrote:
>On Oct 10, 1:57 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
>
>> And how you can say "nothign to do with the increments
>> by which the camera's controls change the exposure" and
>> then describe camera controls changing the
>> exposure... is amusing.
>
>I think he meant the increments on the controls are arbitrary(1/3,
>1/2, or 1 stop for each click on the dials.
But that does happen to be *exactly* where the term "stop" came
from.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>On Oct 10, 1:57 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
>
>> And how you can say "nothign to do with the increments
>> by which the camera's controls change the exposure" and
>> then describe camera controls changing the
>> exposure... is amusing.
>
>I think he meant the increments on the controls are arbitrary(1/3,
>1/2, or 1 stop for each click on the dials.
But that does happen to be *exactly* where the term "stop" came
from.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
> >I think he meant the increments on the controls are arbitrary(1/3,
> >1/2, or 1 stop for each click on the dials.
>
> But that does happen to be *exactly* where the term "stop" came
> from.
I'll let you and Alan figure out where "stop" came from.
The amount of change in exposure per click on the dials on my DSLR is
arbitrary, I choose how much I want.
> >1/2, or 1 stop for each click on the dials.
>
> But that does happen to be *exactly* where the term "stop" came
> from.
I'll let you and Alan figure out where "stop" came from.
The amount of change in exposure per click on the dials on my DSLR is
arbitrary, I choose how much I want.
| |
|
Porte Rouge wrote:
>
>>> I think he meant the increments on the controls are arbitrary(1/3,
>>> 1/2, or 1 stop for each click on the dials.
>>
>> But that does happen to be *exactly* where the term "stop" came
>> from.
>
> I'll let you and Alan figure out where "stop" came from.
>
> The amount of change in exposure per click on the dials on my DSLR
> is arbitrary, I choose how much I want.
Right. And those increments have nothing to do with what I was talking
about - you get that, don't you? :- )
>
>>> I think he meant the increments on the controls are arbitrary(1/3,
>>> 1/2, or 1 stop for each click on the dials.
>>
>> But that does happen to be *exactly* where the term "stop" came
>> from.
>
> I'll let you and Alan figure out where "stop" came from.
>
> The amount of change in exposure per click on the dials on my DSLR
> is arbitrary, I choose how much I want.
Right. And those increments have nothing to do with what I was talking
about - you get that, don't you? :- )
| |
|
"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
news:87d44vn1t3.fld@apaflo.com
> sigh... <sigh@noaddress.com> wrote:
[...]
> Obviously there *is* a huge volume of information
> available in a histogram; and very little of it has
> anything at all to do with setting exposure. E.g., the
> *contrast* information does *not* help set exposure.
Nobody ever said it did. That straw man with you are obsessed has been
exploded several times. The only thing setting contrast to minimum does (in
this context) is expand the histogram so that it more accurately depicts the
dynamic range in the Raw image so that the photographer can make a more
informed decision about what if anything to *subsequently* do to the
exposure. Everybody can see it except you and that is the only claim that
has been made for it (except by you).
news:87d44vn1t3.fld@apaflo.com
> sigh... <sigh@noaddress.com> wrote:
[...]
> Obviously there *is* a huge volume of information
> available in a histogram; and very little of it has
> anything at all to do with setting exposure. E.g., the
> *contrast* information does *not* help set exposure.
Nobody ever said it did. That straw man with you are obsessed has been
exploded several times. The only thing setting contrast to minimum does (in
this context) is expand the histogram so that it more accurately depicts the
dynamic range in the Raw image so that the photographer can make a more
informed decision about what if anything to *subsequently* do to the
exposure. Everybody can see it except you and that is the only claim that
has been made for it (except by you).
| |
|
"DRS" <drs@removethis.ihug.com.au> wrote:
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87d44vn1t3.fld@apaflo.com
>> sigh... <sigh@noaddress.com> wrote:
>
>[...]
>
>> Obviously there *is* a huge volume of information
>> available in a histogram; and very little of it has
>> anything at all to do with setting exposure. E.g., the
>> *contrast* information does *not* help set exposure.
>
>Nobody ever said it did.
Well, not more than 100 or so times in this thread.
>That straw man with you are obsessed has been
>exploded several times.
*What* *has* *been* *exposed* *is* *that* *you* *can't* *cut* *the* *mustard*.
All those claims of knowning everything about
histograms, and when asked to give an analysis of two
examples you could not produce.
>The only thing setting contrast to minimum does (in
>this context) is expand the histogram so that it more accurately depicts the
>dynamic range in the Raw image so that the photographer can make a more
>informed decision about what if anything to *subsequently* do to the
>exposure.
You say "Nobody ever said it did", and then once again
claim it does. What nobody has ever claimed is that
*anything* thing works until *subsequently* to an
exposure! Your remarks are illogical weasel words.
>Everybody can see it except you and that is the only claim that
>has been made for it (except by you).
Everybody realizes that the process is to make an
exposure and then subsequently make exposure adjustments
based on what the histogram shows before making another
exposure.
The problem is that setting the camera for low contrast
isn't very useful, and might even make some (high key
image) histograms more difficult to read.
The *valid* way to make a histogram more useful is to
make it more accurate. That can be done by changing the
White Balance adustment of the camera. (A fact you
would recognize if you actually understood what
histograms are.)
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87d44vn1t3.fld@apaflo.com
>> sigh... <sigh@noaddress.com> wrote:
>
>[...]
>
>> Obviously there *is* a huge volume of information
>> available in a histogram; and very little of it has
>> anything at all to do with setting exposure. E.g., the
>> *contrast* information does *not* help set exposure.
>
>Nobody ever said it did.
Well, not more than 100 or so times in this thread.
>That straw man with you are obsessed has been
>exploded several times.
*What* *has* *been* *exposed* *is* *that* *you* *can't* *cut* *the* *mustard*.
All those claims of knowning everything about
histograms, and when asked to give an analysis of two
examples you could not produce.
>The only thing setting contrast to minimum does (in
>this context) is expand the histogram so that it more accurately depicts the
>dynamic range in the Raw image so that the photographer can make a more
>informed decision about what if anything to *subsequently* do to the
>exposure.
You say "Nobody ever said it did", and then once again
claim it does. What nobody has ever claimed is that
*anything* thing works until *subsequently* to an
exposure! Your remarks are illogical weasel words.
>Everybody can see it except you and that is the only claim that
>has been made for it (except by you).
Everybody realizes that the process is to make an
exposure and then subsequently make exposure adjustments
based on what the histogram shows before making another
exposure.
The problem is that setting the camera for low contrast
isn't very useful, and might even make some (high key
image) histograms more difficult to read.
The *valid* way to make a histogram more useful is to
make it more accurate. That can be done by changing the
White Balance adustment of the camera. (A fact you
would recognize if you actually understood what
histograms are.)
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
DRS wrote:
> Floyd L. Davidson wrote:
>>
>> Obviously there *is* a huge volume of information
>> available in a histogram; and very little of it has
>> anything at all to do with setting exposure. E.g., the
>> *contrast* information does *not* help set exposure.
>
> Nobody ever said it did. That straw man with you are obsessed has been
> exploded several times. The only thing setting contrast to minimum does
> (in this context) is expand the histogram so that it more accurately
> depicts the dynamic range in the Raw image so that the photographer can
> make a more informed decision about what if anything to *subsequently* do
> to the exposure. Everybody can see it except you and that is the only
> claim that has been made for it (except by you).
Floyd is arguing with the demons in his head (and losing).
Is there anything else left to discuss amongst the rest of us?
> Floyd L. Davidson wrote:
>>
>> Obviously there *is* a huge volume of information
>> available in a histogram; and very little of it has
>> anything at all to do with setting exposure. E.g., the
>> *contrast* information does *not* help set exposure.
>
> Nobody ever said it did. That straw man with you are obsessed has been
> exploded several times. The only thing setting contrast to minimum does
> (in this context) is expand the histogram so that it more accurately
> depicts the dynamic range in the Raw image so that the photographer can
> make a more informed decision about what if anything to *subsequently* do
> to the exposure. Everybody can see it except you and that is the only
> claim that has been made for it (except by you).
Floyd is arguing with the demons in his head (and losing).
Is there anything else left to discuss amongst the rest of us?
| |
|
"Wilba" <usenet@CUTTHISimago.com.au> wrote:
>DRS wrote:
>> Floyd L. Davidson wrote:
>>>
>>> Obviously there *is* a huge volume of information
>>> available in a histogram; and very little of it has
>>> anything at all to do with setting exposure. E.g., the
>>> *contrast* information does *not* help set exposure.
>>
>> Nobody ever said it did. That straw man with you are obsessed has been
>> exploded several times. The only thing setting contrast to minimum does
>> (in this context) is expand the histogram so that it more accurately
>> depicts the dynamic range in the Raw image so that the photographer can
>> make a more informed decision about what if anything to *subsequently* do
>> to the exposure. Everybody can see it except you and that is the only
>> claim that has been made for it (except by you).
>
>Floyd is arguing with the demons in his head (and losing).
>
>Is there anything else left to discuss amongst the rest of us?
Another article from Wibla with *nothing* but gratuitous
insults.
But what purpose is there in hurling insults at someone
just because you are unable to understand the topic well
enough to digest technical discussion about it? You've
demonstrated that you can't even measure the difference
between the so called headroom of RAW data over JPEG,
yet you want to argue the fine points of histogram
accuracy???? That is an absurd contradiction.
Neither you nor DRS were even able to analyze a couple of
fairly simple histograms; so just were *do* you get off
with these insults?
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>DRS wrote:
>> Floyd L. Davidson wrote:
>>>
>>> Obviously there *is* a huge volume of information
>>> available in a histogram; and very little of it has
>>> anything at all to do with setting exposure. E.g., the
>>> *contrast* information does *not* help set exposure.
>>
>> Nobody ever said it did. That straw man with you are obsessed has been
>> exploded several times. The only thing setting contrast to minimum does
>> (in this context) is expand the histogram so that it more accurately
>> depicts the dynamic range in the Raw image so that the photographer can
>> make a more informed decision about what if anything to *subsequently* do
>> to the exposure. Everybody can see it except you and that is the only
>> claim that has been made for it (except by you).
>
>Floyd is arguing with the demons in his head (and losing).
>
>Is there anything else left to discuss amongst the rest of us?
Another article from Wibla with *nothing* but gratuitous
insults.
But what purpose is there in hurling insults at someone
just because you are unable to understand the topic well
enough to digest technical discussion about it? You've
demonstrated that you can't even measure the difference
between the so called headroom of RAW data over JPEG,
yet you want to argue the fine points of histogram
accuracy???? That is an absurd contradiction.
Neither you nor DRS were even able to analyze a couple of
fairly simple histograms; so just were *do* you get off
with these insults?
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
In rec.photo.digital.slr-systems Paul Furman <paul-@-edgehill.net> wrote:
> What about saturation? Reducing saturation seems to give more detail to
> the edges also.
That could be a side effect of chromatic aberration. Do you notice it
when there's no chromatic aberration?
--
Chris Malcolm
> What about saturation? Reducing saturation seems to give more detail to
> the edges also.
That could be a side effect of chromatic aberration. Do you notice it
when there's no chromatic aberration?
--
Chris Malcolm
| |
|
On Fri, 09 Oct 2009 16:05:56 -0500, Hilarity Ensues
<hensues@antispam.org> wrote:
>On Fri, 09 Oct 2009 10:44:52 -0800, floyd@apaflo.com (Floyd L. Davidson)
>wrote:
>
>>
>>And do note that later today I'll post an extensive analysis
>>of each, showing exactly what can be understood from them.
>
>Oh, this is going to be good. Let me go get some popcorn, and a milkshake.
>So when I laugh real hard the milkshake will come streaming out of my nose.
Try not to choke on your tater tots.
<hensues@antispam.org> wrote:
>On Fri, 09 Oct 2009 10:44:52 -0800, floyd@apaflo.com (Floyd L. Davidson)
>wrote:
>
>>
>>And do note that later today I'll post an extensive analysis
>>of each, showing exactly what can be understood from them.
>
>Oh, this is going to be good. Let me go get some popcorn, and a milkshake.
>So when I laugh real hard the milkshake will come streaming out of my nose.
Try not to choke on your tater tots.
| |
|
On 11 Oct 2009 09:59:27 GMT, Chris Malcolm <cam@holyrood.ed.ac.uk>
wrote:
>In rec.photo.digital.slr-systems Paul Furman <paul-@-edgehill.net> wrote:
>
>> What about saturation? Reducing saturation seems to give more detail to
>> the edges also.
>
>That could be a side effect of chromatic aberration. Do you notice it
>when there's no chromatic aberration?
Or from chroma subsampling if you're working with jpegs.
wrote:
>In rec.photo.digital.slr-systems Paul Furman <paul-@-edgehill.net> wrote:
>
>> What about saturation? Reducing saturation seems to give more detail to
>> the edges also.
>
>That could be a side effect of chromatic aberration. Do you notice it
>when there's no chromatic aberration?
Or from chroma subsampling if you're working with jpegs.
| |
|
On Oct 10, 3:30 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
> sigh... <s...@noaddress.com> wrote:
> >On Thu, 08 Oct 2009 18:36:37 -0800, fl...@apaflo.com (Floyd L. Davidson)
> >wrote:
> Setting White Balance will have a dramatic effect of the
> accuracy of both.
Could you tell me how you go about setting the white balance on your
camera? I read this page:
http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm
The first method is over my head and I have a Nikon that doesn't use
saturated pixels for the calculation of white balance. My white
balance can be set to Auto(+ or - 3), by lighting(tungsten,
fluorescent, flash), outside light (direct sun, shade, cloudy), select
a temperature, and presets(measure a gray card or use WB from another
photo). Which would you recommend?
Porte
> sigh... <s...@noaddress.com> wrote:
> >On Thu, 08 Oct 2009 18:36:37 -0800, fl...@apaflo.com (Floyd L. Davidson)
> >wrote:
> Setting White Balance will have a dramatic effect of the
> accuracy of both.
Could you tell me how you go about setting the white balance on your
camera? I read this page:
http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm
The first method is over my head and I have a Nikon that doesn't use
saturated pixels for the calculation of white balance. My white
balance can be set to Auto(+ or - 3), by lighting(tungsten,
fluorescent, flash), outside light (direct sun, shade, cloudy), select
a temperature, and presets(measure a gray card or use WB from another
photo). Which would you recommend?
Porte
| |
|
Porte Rouge <porterougeman@gmail.com> wrote:
>On Oct 10, 3:30 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
>> sigh... <s...@noaddress.com> wrote:
>> >On Thu, 08 Oct 2009 18:36:37 -0800, fl...@apaflo.com (Floyd L. Davidson)
>> >wrote:
>
>> Setting White Balance will have a dramatic effect of the
>> accuracy of both.
>
>Could you tell me how you go about setting the white balance on your
>camera? I read this page:
>
>http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm
>
>The first method is over my head and I have a Nikon that doesn't use
>saturated pixels for the calculation of white balance. My white
>balance can be set to Auto(+ or - 3), by lighting(tungsten,
>fluorescent, flash), outside light (direct sun, shade, cloudy), select
>a temperature, and presets(measure a gray card or use WB from another
>photo). Which would you recommend?
I use Nikon cameras and shoot RAW+JPEG virtually all of
the time, using the JPEG for preview only and process
RAW files for production. The JPEG is often enough
previewed using the camera's LCD (I show somebody a shot
that was just made, or even let them scroll through
several images), but is usually seen via a laptop LCD.
Hence a realistic JPEG is important, but does not need
to be perfect.
Also, I use the histogram as a rough indicator of
exposure, and the "highlight" display to actually decide
if an image was exposed correctly.
I always use "Auto" for White Balance. The significant
effect of doing so, for my workflow, is that the camera
records whatever multipliers were used. If a preset WB
setting is used, the preset multipliers are recorded,
but we already know what those values are so recording
them is not useful (they are also used as preset values by
the raw converter). By using "Auto" I get a record of
what the camera thought WB should be.
When I process the RAW file (I use UFRAW) I can use the
camera generated auto values or I can use what the
program's "auto" setting generates. Sometimes they are
very similar, sometimes not, but usually one or the
other is close enough to what I want to provide a
starting point for manual adjustment of the program's
White Balance.
I have tried the UniWB concept, and it certainly works
as described. It was nice to have a very accurate JPEG
in terms of the histogram's indication of exposure,
but... I can't live with the greenish looking JPEGs
produced. :-) I can live with knowing that to nail
exposure I need to allow at least some portion of the
image to blink in the highlight display. I just keep in
mind that getting more dynamic range means a little more
area blinking, and positively avoiding clipped
highlights means a little less. It's a judgement call
that depends on circumstances, and in any case is never
very critical.
A lot of folks say what they want is an histogram
generated directly from the camera's raw data.
Un-interpolated raw data histograms aren't very useful
though! What I would like to see is the camera do one
interpolation for the JPEG image and an entirely
separate interpolation for a histogram. For those who
shoot JPEG, the settings would be the same (or just use
the JPEG for the histogram as is now done). For those
who shoot RAW the interpolation could be set for using
1.0 multipliers, low saturation, no sharpening, and
a standard gamma, to get a very accurate histogram.
I wouldn't mind seeing an "expanded" histogram display
either, where the entire graph shows only the upper 2
fstops of the histogram and also truncates the vertical
range by 1/2. What a tool that would be!
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>On Oct 10, 3:30 am, fl...@apaflo.com (Floyd L. Davidson) wrote:
>> sigh... <s...@noaddress.com> wrote:
>> >On Thu, 08 Oct 2009 18:36:37 -0800, fl...@apaflo.com (Floyd L. Davidson)
>> >wrote:
>
>> Setting White Balance will have a dramatic effect of the
>> accuracy of both.
>
>Could you tell me how you go about setting the white balance on your
>camera? I read this page:
>
>http://www.guillermoluijk.com/tutorial/uniwb/index_en.htm
>
>The first method is over my head and I have a Nikon that doesn't use
>saturated pixels for the calculation of white balance. My white
>balance can be set to Auto(+ or - 3), by lighting(tungsten,
>fluorescent, flash), outside light (direct sun, shade, cloudy), select
>a temperature, and presets(measure a gray card or use WB from another
>photo). Which would you recommend?
I use Nikon cameras and shoot RAW+JPEG virtually all of
the time, using the JPEG for preview only and process
RAW files for production. The JPEG is often enough
previewed using the camera's LCD (I show somebody a shot
that was just made, or even let them scroll through
several images), but is usually seen via a laptop LCD.
Hence a realistic JPEG is important, but does not need
to be perfect.
Also, I use the histogram as a rough indicator of
exposure, and the "highlight" display to actually decide
if an image was exposed correctly.
I always use "Auto" for White Balance. The significant
effect of doing so, for my workflow, is that the camera
records whatever multipliers were used. If a preset WB
setting is used, the preset multipliers are recorded,
but we already know what those values are so recording
them is not useful (they are also used as preset values by
the raw converter). By using "Auto" I get a record of
what the camera thought WB should be.
When I process the RAW file (I use UFRAW) I can use the
camera generated auto values or I can use what the
program's "auto" setting generates. Sometimes they are
very similar, sometimes not, but usually one or the
other is close enough to what I want to provide a
starting point for manual adjustment of the program's
White Balance.
I have tried the UniWB concept, and it certainly works
as described. It was nice to have a very accurate JPEG
in terms of the histogram's indication of exposure,
but... I can't live with the greenish looking JPEGs
produced. :-) I can live with knowing that to nail
exposure I need to allow at least some portion of the
image to blink in the highlight display. I just keep in
mind that getting more dynamic range means a little more
area blinking, and positively avoiding clipped
highlights means a little less. It's a judgement call
that depends on circumstances, and in any case is never
very critical.
A lot of folks say what they want is an histogram
generated directly from the camera's raw data.
Un-interpolated raw data histograms aren't very useful
though! What I would like to see is the camera do one
interpolation for the JPEG image and an entirely
separate interpolation for a histogram. For those who
shoot JPEG, the settings would be the same (or just use
the JPEG for the histogram as is now done). For those
who shoot RAW the interpolation could be set for using
1.0 multipliers, low saturation, no sharpening, and
a standard gamma, to get a very accurate histogram.
I wouldn't mind seeing an "expanded" histogram display
either, where the entire graph shows only the upper 2
fstops of the histogram and also truncates the vertical
range by 1/2. What a tool that would be!
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
Paul Furman wrote:
> OK, this makes sense, the posterizing issue is not really visible in any
> sort of normal exposure. What about Floyd's comment below that the noise
> level remains the same but exposing to the right increases the signal so
> that overwhelms the noise? That seems to tie the two together in a
> comprehensible way.
Look at it this way: Your RAW image will have the same amount of noise,
regardless of the exposure. But exposing to the right will lift the
shadow levels up higher, relative to the noise. When you process the RAW
image on your PC, you'll lower the brightness levels back down, thus
lowering the absolute noise levels with them.
More technically, you're maximising the signal-to-noise ratio.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
> OK, this makes sense, the posterizing issue is not really visible in any
> sort of normal exposure. What about Floyd's comment below that the noise
> level remains the same but exposing to the right increases the signal so
> that overwhelms the noise? That seems to tie the two together in a
> comprehensible way.
Look at it this way: Your RAW image will have the same amount of noise,
regardless of the exposure. But exposing to the right will lift the
shadow levels up higher, relative to the noise. When you process the RAW
image on your PC, you'll lower the brightness levels back down, thus
lowering the absolute noise levels with them.
More technically, you're maximising the signal-to-noise ratio.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
| |
|
DRS wrote:
> "Alan Browne" <alan.browne@FreelunchVideotron.ca> wrote in message
> news:bomdnVV2DovNOVLXnZ2dnUVZ_qWdnZ2d@giganews.com
>> sigh... wrote:
>
> [...]
>
>>> Nothing can be determined from either without the accompanying
>>> photograph.
>> BS. It's clear that the first one was mostly shadow, probably a black
>> card (or underexposed grey card). There may have been a shiny patch,
>> or perhaps a white edge to explain the bumps on the right...
>
> It was a night shot landscape with a blue cast. The moon provide the
> smattering of pixels on the right.
>
>> The second a white card (or over exposed grey card).
>
> It was a snow-laden tree surrounded by snow. The image had a hint of fog.
> All those whites and light grays predictably pushed everything over to the
> right.
>
>> This is so easy to replicate...
>
> True. And it also manages to avoid the point (not you, Floyd).
For nothing more than confirmation I just replicated the same results as
in the links (minus the white over grey point) using an old grey card.
Any adjustment of flash output, aperture or ISO generated the same
results (although a narrower histo than in the links).
No surprise. I could have added a small white disk to the grey card to
get the additional data to the right (emulate the "moon" in dark sky
image).
Same could be done with a white card or black card.
> "Alan Browne" <alan.browne@FreelunchVideotron.ca> wrote in message
> news:bomdnVV2DovNOVLXnZ2dnUVZ_qWdnZ2d@giganews.com
>> sigh... wrote:
>
> [...]
>
>>> Nothing can be determined from either without the accompanying
>>> photograph.
>> BS. It's clear that the first one was mostly shadow, probably a black
>> card (or underexposed grey card). There may have been a shiny patch,
>> or perhaps a white edge to explain the bumps on the right...
>
> It was a night shot landscape with a blue cast. The moon provide the
> smattering of pixels on the right.
>
>> The second a white card (or over exposed grey card).
>
> It was a snow-laden tree surrounded by snow. The image had a hint of fog.
> All those whites and light grays predictably pushed everything over to the
> right.
>
>> This is so easy to replicate...
>
> True. And it also manages to avoid the point (not you, Floyd).
For nothing more than confirmation I just replicated the same results as
in the links (minus the white over grey point) using an old grey card.
Any adjustment of flash output, aperture or ISO generated the same
results (although a narrower histo than in the links).
No surprise. I could have added a small white disk to the grey card to
get the additional data to the right (emulate the "moon" in dark sky
image).
Same could be done with a white card or black card.
| |
|
John A. wrote:
> On 11 Oct 2009 09:59:27 GMT, Chris Malcolm <cam@holyrood.ed.ac.uk>
> wrote:
>
>> In rec.photo.digital.slr-systems Paul Furman <paul-@-edgehill.net> wrote:
>>
>>> What about saturation? Reducing saturation seems to give more detail to
>>> the edges also.
>> That could be a side effect of chromatic aberration. Do you notice it
>> when there's no chromatic aberration?
>
> Or from chroma subsampling if you're working with jpegs.
I don't think either would have much effect. It looks to make as big of
a difference as contrast.
--
Paul Furman
www.edgehill.net
www.baynatives.com
all google groups messages filtered due to spam
> On 11 Oct 2009 09:59:27 GMT, Chris Malcolm <cam@holyrood.ed.ac.uk>
> wrote:
>
>> In rec.photo.digital.slr-systems Paul Furman <paul-@-edgehill.net> wrote:
>>
>>> What about saturation? Reducing saturation seems to give more detail to
>>> the edges also.
>> That could be a side effect of chromatic aberration. Do you notice it
>> when there's no chromatic aberration?
>
> Or from chroma subsampling if you're working with jpegs.
I don't think either would have much effect. It looks to make as big of
a difference as contrast.
--
Paul Furman
www.edgehill.net
www.baynatives.com
all google groups messages filtered due to spam
| |
|
So, with WB all set you take a picture. I gather that you expose to
the right? My sunrise is good example of lighting conditions that
lead to especially washed out colors if you do. How do you adjust the
colors in post or do you just meter for the sunrise and let the
histogram fall where it may. When I shot slide film I would spot meter
on an area that I knew what the meter should read and set exposure
accordingly, and in digital this also yields a good looking sunrise.
The histogram, however, is not as far to the right as it could be.
Porte
the right? My sunrise is good example of lighting conditions that
lead to especially washed out colors if you do. How do you adjust the
colors in post or do you just meter for the sunrise and let the
histogram fall where it may. When I shot slide film I would spot meter
on an area that I knew what the meter should read and set exposure
accordingly, and in digital this also yields a good looking sunrise.
The histogram, however, is not as far to the right as it could be.
Porte
| |
|
Porte Rouge <porterougeman@gmail.com> wrote:
>So, with WB all set you take a picture. I gather that you expose to
>the right? My sunrise is good example of lighting conditions that
>lead to especially washed out colors if you do. How do you adjust the
>colors in post or do you just meter for the sunrise and let the
>histogram fall where it may.
If you don't want any part of the scene to clip, then
shoot the sunrize ETTR. It is *absolutely* necessary to
post process, where you set the exposure for whatever
effect you like. ETTR does *not* cause washed out
colors (inappropriate post processing might though).
>When I shot slide film I would spot meter
>on an area that I knew what the meter should read and set exposure
>accordingly, and in digital this also yields a good looking sunrise.
>The histogram, however, is not as far to the right as it could be.
How can you spot meter on an area that "I knew what the
meter would read"??? I don't understand what you mean
by that statement.
If the histogram is not as far to the right as it could
be your image does not have as wide a dynamic range as
the camera is capable of recording. The shadow areas
will have more noise than if it were exposed per ETTR.
If you want any specific *final* tone levels, set it
that way in post processing. In essence, in post
processing drop the "exposure" to make the editor's
histogram show what you think the camera's should have
shown absent ETTR adjustments.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>So, with WB all set you take a picture. I gather that you expose to
>the right? My sunrise is good example of lighting conditions that
>lead to especially washed out colors if you do. How do you adjust the
>colors in post or do you just meter for the sunrise and let the
>histogram fall where it may.
If you don't want any part of the scene to clip, then
shoot the sunrize ETTR. It is *absolutely* necessary to
post process, where you set the exposure for whatever
effect you like. ETTR does *not* cause washed out
colors (inappropriate post processing might though).
>When I shot slide film I would spot meter
>on an area that I knew what the meter should read and set exposure
>accordingly, and in digital this also yields a good looking sunrise.
>The histogram, however, is not as far to the right as it could be.
How can you spot meter on an area that "I knew what the
meter would read"??? I don't understand what you mean
by that statement.
If the histogram is not as far to the right as it could
be your image does not have as wide a dynamic range as
the camera is capable of recording. The shadow areas
will have more noise than if it were exposed per ETTR.
If you want any specific *final* tone levels, set it
that way in post processing. In essence, in post
processing drop the "exposure" to make the editor's
histogram show what you think the camera's should have
shown absent ETTR adjustments.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
> If you don't want any part of the scene to clip, then
> shoot the sunrize ETTR. It is *absolutely* necessary to
> post process, where you set the exposure for whatever
> effect you like. ETTR does *not* cause washed out
> colors (inappropriate post processing might though).
By "washed out" I mean the image is brighter than what I saw when I
took the picture and to get the image to represent what I saw I need
to darken the image. By either reducing exposure or some other method
in post.
> >When I shot slide film I would spot meter
> >on an area that I knew what the meter should read and set exposure
> >accordingly, and in digital this also yields a good looking sunrise.
> >The histogram, however, is not as far to the right as it could be.
>
> How can you spot meter on an area that "I knew what the
> meter would read"??? I don't understand what you mean
> by that statement.
I spot meter on something that, from experience, I know what I want
the light meter to indicate for exposure. For example (for film, no
ETTR), a gray cloud I set exposure so the meter reads in the middle of
the exposure display, a white cloud plus 1 or 2 stops, a black cloud
minus 1 or 2 stops.
> If the histogram is not as far to the right as it could
> be your image does not have as wide a dynamic range as
> the camera is capable of recording. The shadow areas
> will have more noise than if it were exposed per ETTR.
> If you want any specific *final* tone levels, set it
> that way in post processing. In essence, in post
> processing drop the "exposure" to make the editor's
> histogram show what you think the camera's should have
> shown absent ETTR adjustments.
Do you specifically reduce the exposure in post or some other method?
There are exposure sliders in ACR and Lightroom, as well as CS4.
Porte
> shoot the sunrize ETTR. It is *absolutely* necessary to
> post process, where you set the exposure for whatever
> effect you like. ETTR does *not* cause washed out
> colors (inappropriate post processing might though).
By "washed out" I mean the image is brighter than what I saw when I
took the picture and to get the image to represent what I saw I need
to darken the image. By either reducing exposure or some other method
in post.
> >When I shot slide film I would spot meter
> >on an area that I knew what the meter should read and set exposure
> >accordingly, and in digital this also yields a good looking sunrise.
> >The histogram, however, is not as far to the right as it could be.
>
> How can you spot meter on an area that "I knew what the
> meter would read"??? I don't understand what you mean
> by that statement.
I spot meter on something that, from experience, I know what I want
the light meter to indicate for exposure. For example (for film, no
ETTR), a gray cloud I set exposure so the meter reads in the middle of
the exposure display, a white cloud plus 1 or 2 stops, a black cloud
minus 1 or 2 stops.
> If the histogram is not as far to the right as it could
> be your image does not have as wide a dynamic range as
> the camera is capable of recording. The shadow areas
> will have more noise than if it were exposed per ETTR.
> If you want any specific *final* tone levels, set it
> that way in post processing. In essence, in post
> processing drop the "exposure" to make the editor's
> histogram show what you think the camera's should have
> shown absent ETTR adjustments.
Do you specifically reduce the exposure in post or some other method?
There are exposure sliders in ACR and Lightroom, as well as CS4.
Porte
| |
|
Steven Redgate <stevered3@gmail.com> wrote:
>> If you don't want any part of the scene to clip, then
>> shoot the sunrize ETTR. It is *absolutely* necessary to
>> post process, where you set the exposure for whatever
>> effect you like. ETTR does *not* cause washed out
>> colors (inappropriate post processing might though).
>
>By "washed out" I mean the image is brighter than what I saw when I
>took the picture and to get the image to represent what I saw I need
>to darken the image. By either reducing exposure or some other method
>in post.
You are aware that ETTR is a two part process, part one
being boost the exposure to maximum possible, and part
two is to later reduce it to whatever it is that makes
your heart beat fast enough.
You *have* to do both.
>> >When I shot slide film I would spot meter
>> >on an area that I knew what the meter should read and set exposure
>> >accordingly, and in digital this also yields a good looking sunrise.
>> >The histogram, however, is not as far to the right as it could be.
>>
>> How can you spot meter on an area that "I knew what the
>> meter would read"??? I don't understand what you mean
>> by that statement.
>
>I spot meter on something that, from experience, I know what I want
>the light meter to indicate for exposure. For example (for film, no
>ETTR), a gray cloud I set exposure so the meter reads in the middle of
>the exposure display, a white cloud plus 1 or 2 stops, a black cloud
>minus 1 or 2 stops.
So you take wild guesses at what shade various parts of the
scene are! (Isn't the whole idea of a meter supposed to be
to get away from these wild guesses about exposure??? :-)
Sarcasm aside (because certainly with film that was an
almost required method), you don't need to guess any
more. Digital cameras provide tools that will
positively show you where your image is in terms of the
camera's dynamic range capability. That's what a
histogram does.
>> If the histogram is not as far to the right as it could
>> be your image does not have as wide a dynamic range as
>> the camera is capable of recording. The shadow areas
>> will have more noise than if it were exposed per ETTR.
>> If you want any specific *final* tone levels, set it
>> that way in post processing. In essence, in post
>> processing drop the "exposure" to make the editor's
>> histogram show what you think the camera's should have
>> shown absent ETTR adjustments.
>
>Do you specifically reduce the exposure in post or some other method?
>There are exposure sliders in ACR and Lightroom, as well as CS4.
Yes, in post processing.
In the camera, try to set exposure as high as is
possible. The closer to clipping the better (indeed,
clipping of some types of highlights might be perfectly
okay). The camera is essentially going to record the
same amount of noise regardless of your exposure
settings, so increasing exposure increases the
Signal-To-Noise-Ratio.
In post processing reduce exposure (which reduces noise
at the same amount it does the highlights) to give the
desired brightness.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>> If you don't want any part of the scene to clip, then
>> shoot the sunrize ETTR. It is *absolutely* necessary to
>> post process, where you set the exposure for whatever
>> effect you like. ETTR does *not* cause washed out
>> colors (inappropriate post processing might though).
>
>By "washed out" I mean the image is brighter than what I saw when I
>took the picture and to get the image to represent what I saw I need
>to darken the image. By either reducing exposure or some other method
>in post.
You are aware that ETTR is a two part process, part one
being boost the exposure to maximum possible, and part
two is to later reduce it to whatever it is that makes
your heart beat fast enough.
You *have* to do both.
>> >When I shot slide film I would spot meter
>> >on an area that I knew what the meter should read and set exposure
>> >accordingly, and in digital this also yields a good looking sunrise.
>> >The histogram, however, is not as far to the right as it could be.
>>
>> How can you spot meter on an area that "I knew what the
>> meter would read"??? I don't understand what you mean
>> by that statement.
>
>I spot meter on something that, from experience, I know what I want
>the light meter to indicate for exposure. For example (for film, no
>ETTR), a gray cloud I set exposure so the meter reads in the middle of
>the exposure display, a white cloud plus 1 or 2 stops, a black cloud
>minus 1 or 2 stops.
So you take wild guesses at what shade various parts of the
scene are! (Isn't the whole idea of a meter supposed to be
to get away from these wild guesses about exposure??? :-)
Sarcasm aside (because certainly with film that was an
almost required method), you don't need to guess any
more. Digital cameras provide tools that will
positively show you where your image is in terms of the
camera's dynamic range capability. That's what a
histogram does.
>> If the histogram is not as far to the right as it could
>> be your image does not have as wide a dynamic range as
>> the camera is capable of recording. The shadow areas
>> will have more noise than if it were exposed per ETTR.
>> If you want any specific *final* tone levels, set it
>> that way in post processing. In essence, in post
>> processing drop the "exposure" to make the editor's
>> histogram show what you think the camera's should have
>> shown absent ETTR adjustments.
>
>Do you specifically reduce the exposure in post or some other method?
>There are exposure sliders in ACR and Lightroom, as well as CS4.
Yes, in post processing.
In the camera, try to set exposure as high as is
possible. The closer to clipping the better (indeed,
clipping of some types of highlights might be perfectly
okay). The camera is essentially going to record the
same amount of noise regardless of your exposure
settings, so increasing exposure increases the
Signal-To-Noise-Ratio.
In post processing reduce exposure (which reduces noise
at the same amount it does the highlights) to give the
desired brightness.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
Steven Redgate wrote:
>> If you don't want any part of the scene to clip, then
>> shoot the sunrize ETTR. It is *absolutely* necessary to
>> post process, where you set the exposure for whatever
>> effect you like. ETTR does *not* cause washed out
>> colors (inappropriate post processing might though).
>
> By "washed out" I mean the image is brighter than what I saw when I
> took the picture and to get the image to represent what I saw I need
> to darken the image. By either reducing exposure or some other method
> in post.
Correct. You can reduce the exposure slider, or you can move the black
level on the tone curve to the left hand side of the histogram (which is
what I do), which retains the highlights.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
>> If you don't want any part of the scene to clip, then
>> shoot the sunrize ETTR. It is *absolutely* necessary to
>> post process, where you set the exposure for whatever
>> effect you like. ETTR does *not* cause washed out
>> colors (inappropriate post processing might though).
>
> By "washed out" I mean the image is brighter than what I saw when I
> took the picture and to get the image to represent what I saw I need
> to darken the image. By either reducing exposure or some other method
> in post.
Correct. You can reduce the exposure slider, or you can move the black
level on the tone curve to the left hand side of the histogram (which is
what I do), which retains the highlights.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
| |
|
> You are aware that ETTR is a two part process, part one
> being boost the exposure to maximum possible, and part
> two is to later reduce it to whatever it is that makes
> your heart beat fast enough.
>
> You *have* to do both.
>
Yes, I understand. My question is, after ETTR what exactly do you
yourself do in post processing. Do you adjust exposure, black point,
or something else?
> >> >When I shot slide film I would spot meter
> >> >on an area that I knew what the meter should read and set exposure
> >> >accordingly, and in digital this also yields a good looking sunrise.
> >> >The histogram, however, is not as far to the right as it could be.
>
> >> How can you spot meter on an area that "I knew what the
> >> meter would read"??? I don't understand what you mean
> >> by that statement.
>
> >I spot meter on something that, from experience, I know what I want
> >the light meter to indicate for exposure. For example (for film, no
> >ETTR), a gray cloud I set exposure so the meter reads in the middle of
> >the exposure display, a white cloud plus 1 or 2 stops, a black cloud
> >minus 1 or 2 stops.
>
> So you take wild guesses at what shade various parts of the
> scene are! (Isn't the whole idea of a meter supposed to be
> to get away from these wild guesses about exposure??? :-)
>
It's not really a wild guess. It's like the earlier post about the
snow bank. I was taught and learned that if I spot metered the snow
and set exposure so the exposure display read dead center, the snow
would be gray in the photo. If I use 1 or 2 stops more exposure it
will be whiter. If I spot meter the black dog and the exposure meter
is centered the dog will be gray, so I use less exposure and it will
be darker.
Porte
> being boost the exposure to maximum possible, and part
> two is to later reduce it to whatever it is that makes
> your heart beat fast enough.
>
> You *have* to do both.
>
Yes, I understand. My question is, after ETTR what exactly do you
yourself do in post processing. Do you adjust exposure, black point,
or something else?
> >> >When I shot slide film I would spot meter
> >> >on an area that I knew what the meter should read and set exposure
> >> >accordingly, and in digital this also yields a good looking sunrise.
> >> >The histogram, however, is not as far to the right as it could be.
>
> >> How can you spot meter on an area that "I knew what the
> >> meter would read"??? I don't understand what you mean
> >> by that statement.
>
> >I spot meter on something that, from experience, I know what I want
> >the light meter to indicate for exposure. For example (for film, no
> >ETTR), a gray cloud I set exposure so the meter reads in the middle of
> >the exposure display, a white cloud plus 1 or 2 stops, a black cloud
> >minus 1 or 2 stops.
>
> So you take wild guesses at what shade various parts of the
> scene are! (Isn't the whole idea of a meter supposed to be
> to get away from these wild guesses about exposure??? :-)
>
It's not really a wild guess. It's like the earlier post about the
snow bank. I was taught and learned that if I spot metered the snow
and set exposure so the exposure display read dead center, the snow
would be gray in the photo. If I use 1 or 2 stops more exposure it
will be whiter. If I spot meter the black dog and the exposure meter
is centered the dog will be gray, so I use less exposure and it will
be darker.
Porte
| |
|
Porte Rouge <porterougeman@gmail.com> wrote:
>> You are aware that ETTR is a two part process, part one
>> being boost the exposure to maximum possible, and part
>> two is to later reduce it to whatever it is that makes
>> your heart beat fast enough.
>>
>> You *have* to do both.
>
>Yes, I understand. My question is, after ETTR what exactly do you
>yourself do in post processing. Do you adjust exposure, black point,
>or something else?
"After ETTR" means it follows adjusting *exposure* in
post processing.
Incidentally, black point has nothing to do with ETTR or
exposure. For most images if gamma is set correctly
there is no need to move the black point up. Generally
I click on "Auto" for black point, and if it moves the
curve away from the lower right corner I reset it and
review the gamma settings to make sure I've got that
right. Some times it does work out that it helps to
move the black point, but not often.
I adjust exposure, white balance, gamma and linearity,
black point, color saturation and potentially things
like noise reduction and certain lens specific
corrections all with the raw converter. An image editor
is used for resizing, cropping, retouching, USM, borders,
watermarks, etc.
>> >> >When I shot slide film I would spot meter
>> >> >on an area that I knew what the meter should read and set exposure
>> >> >accordingly, and in digital this also yields a good looking sunrise.
>> >> >The histogram, however, is not as far to the right as it could be.
>>
>> >> How can you spot meter on an area that "I knew what the
>> >> meter would read"??? I don't understand what you mean
>> >> by that statement.
>>
>> >I spot meter on something that, from experience, I know what I want
>> >the light meter to indicate for exposure. For example (for film, no
>> >ETTR), a gray cloud I set exposure so the meter reads in the middle of
>> >the exposure display, a white cloud plus 1 or 2 stops, a black cloud
>> >minus 1 or 2 stops.
>>
>> So you take wild guesses at what shade various parts of the
>> scene are! (Isn't the whole idea of a meter supposed to be
>> to get away from these wild guesses about exposure??? :-)
>>
>
>It's not really a wild guess. It's like the earlier post about the
>snow bank. I was taught and learned that if I spot metered the snow
>and set exposure so the exposure display read dead center, the snow
>would be gray in the photo. If I use 1 or 2 stops more exposure it
>will be whiter.
So you take a wild guess at 1 or 2 stops more! Even
with film and no histograms most accomplished
photographers attempted to get within 1/2 a stop.
Today, with digital and histograms, it is entirely
possible to be within 1/3rd of a stop.
This may or may not be obvious (I live 300+ miles north
of the Arctic Circle); but do realize that I literally
take thousands of images that include snow! It really
does require paying attention before hand if you want
detail in the snow, or if it can just be "white" or if
it can be blown out totally. (There is this
false claim that Eskimos have 100 words for snow, which
they don't... but skiers do and so do photographers! :-)
And all of that has to be balanced against the
brightness level for people's faces, black dogs, and
white bears.
>If I spot meter the black dog and the exposure meter
>is centered the dog will be gray, so I use less exposure and it will
>be darker.
You guess at how much darker it should be...
What a spot meter can show you (and a histogram can show
even more easily), is how much of a range you have
between the dog and whatever else there is. If it
happens to be a snow bank, it might well be 7 or 8 stops
difference and arbitarily adjusting the dog to something
that "will be darker" will mean that you lose the
texture of the snow. The trick is realizing that the
dog is going to be off scale, so getting texture on both
the snow and the dog means putting the snow right at the
maximum. Then in post processing the brightness is
adjusted to maintain the snow at just under maximum
white while contrast is adjusted to bring the texture on
the dog out of the black.
It depends on the dynamic range of your camera of
course, but the closer one puts the snow to maximum
white the less noise will show up on the texture of the
dog.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>> You are aware that ETTR is a two part process, part one
>> being boost the exposure to maximum possible, and part
>> two is to later reduce it to whatever it is that makes
>> your heart beat fast enough.
>>
>> You *have* to do both.
>
>Yes, I understand. My question is, after ETTR what exactly do you
>yourself do in post processing. Do you adjust exposure, black point,
>or something else?
"After ETTR" means it follows adjusting *exposure* in
post processing.
Incidentally, black point has nothing to do with ETTR or
exposure. For most images if gamma is set correctly
there is no need to move the black point up. Generally
I click on "Auto" for black point, and if it moves the
curve away from the lower right corner I reset it and
review the gamma settings to make sure I've got that
right. Some times it does work out that it helps to
move the black point, but not often.
I adjust exposure, white balance, gamma and linearity,
black point, color saturation and potentially things
like noise reduction and certain lens specific
corrections all with the raw converter. An image editor
is used for resizing, cropping, retouching, USM, borders,
watermarks, etc.
>> >> >When I shot slide film I would spot meter
>> >> >on an area that I knew what the meter should read and set exposure
>> >> >accordingly, and in digital this also yields a good looking sunrise.
>> >> >The histogram, however, is not as far to the right as it could be.
>>
>> >> How can you spot meter on an area that "I knew what the
>> >> meter would read"??? I don't understand what you mean
>> >> by that statement.
>>
>> >I spot meter on something that, from experience, I know what I want
>> >the light meter to indicate for exposure. For example (for film, no
>> >ETTR), a gray cloud I set exposure so the meter reads in the middle of
>> >the exposure display, a white cloud plus 1 or 2 stops, a black cloud
>> >minus 1 or 2 stops.
>>
>> So you take wild guesses at what shade various parts of the
>> scene are! (Isn't the whole idea of a meter supposed to be
>> to get away from these wild guesses about exposure??? :-)
>>
>
>It's not really a wild guess. It's like the earlier post about the
>snow bank. I was taught and learned that if I spot metered the snow
>and set exposure so the exposure display read dead center, the snow
>would be gray in the photo. If I use 1 or 2 stops more exposure it
>will be whiter.
So you take a wild guess at 1 or 2 stops more! Even
with film and no histograms most accomplished
photographers attempted to get within 1/2 a stop.
Today, with digital and histograms, it is entirely
possible to be within 1/3rd of a stop.
This may or may not be obvious (I live 300+ miles north
of the Arctic Circle); but do realize that I literally
take thousands of images that include snow! It really
does require paying attention before hand if you want
detail in the snow, or if it can just be "white" or if
it can be blown out totally. (There is this
false claim that Eskimos have 100 words for snow, which
they don't... but skiers do and so do photographers! :-)
And all of that has to be balanced against the
brightness level for people's faces, black dogs, and
white bears.
>If I spot meter the black dog and the exposure meter
>is centered the dog will be gray, so I use less exposure and it will
>be darker.
You guess at how much darker it should be...
What a spot meter can show you (and a histogram can show
even more easily), is how much of a range you have
between the dog and whatever else there is. If it
happens to be a snow bank, it might well be 7 or 8 stops
difference and arbitarily adjusting the dog to something
that "will be darker" will mean that you lose the
texture of the snow. The trick is realizing that the
dog is going to be off scale, so getting texture on both
the snow and the dog means putting the snow right at the
maximum. Then in post processing the brightness is
adjusted to maintain the snow at just under maximum
white while contrast is adjusted to bring the texture on
the dog out of the black.
It depends on the dynamic range of your camera of
course, but the closer one puts the snow to maximum
white the less noise will show up on the texture of the
dog.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
> So you take a wild guess at 1 or 2 stops more! Even
> with film and no histograms most accomplished
> photographers attempted to get within 1/2 a stop.
> Today, with digital and histograms, it is entirely
> possible to be within 1/3rd of a stop.
Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
typer, I didn't go into a lot of detail about the metering. I do all
the stuff in your post here, meter, histogram, Photoshop, ACR (thanks
for the link to UFRAW by the way,that looks interesting) I was just
checking to see what other methods people used to correct their photos
in post processing.
> This may or may not be obvious (I live 300+ miles north
> of the Arctic Circle); but do realize that I literally
> take thousands of images that include snow! It really
> does require paying attention before hand if you want
> detail in the snow, or if it can just be "white" or if
> it can be blown out totally. (There is this
> false claim that Eskimos have 100 words for snow, which
> they don't... but skiers do and so do photographers! :-)
>
> And all of that has to be balanced against the
> brightness level for people's faces, black dogs, and
> white bears.
>
> >If I spot meter the black dog and the exposure meter
> >is centered the dog will be gray, so I use less exposure and it will
> >be darker.
>
> You guess at how much darker it should be...
>
> What a spot meter can show you (and a histogram can show
> even more easily), is how much of a range you have
> between the dog and whatever else there is. If it
> happens to be a snow bank, it might well be 7 or 8 stops
> difference and arbitarily adjusting the dog to something
> that "will be darker" will mean that you lose the
> texture of the snow. The trick is realizing that the
> dog is going to be off scale, so getting texture on both
> the snow and the dog means putting the snow right at the
> maximum. Then in post processing the brightness is
> adjusted to maintain the snow at just under maximum
> white while contrast is adjusted to bring the texture on
> the dog out of the black.
>
> It depends on the dynamic range of your camera of
> course, but the closer one puts the snow to maximum
> white the less noise will show up on the texture of the
> dog.
>
> --
> Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
> Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
> with film and no histograms most accomplished
> photographers attempted to get within 1/2 a stop.
> Today, with digital and histograms, it is entirely
> possible to be within 1/3rd of a stop.
Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
typer, I didn't go into a lot of detail about the metering. I do all
the stuff in your post here, meter, histogram, Photoshop, ACR (thanks
for the link to UFRAW by the way,that looks interesting) I was just
checking to see what other methods people used to correct their photos
in post processing.
> This may or may not be obvious (I live 300+ miles north
> of the Arctic Circle); but do realize that I literally
> take thousands of images that include snow! It really
> does require paying attention before hand if you want
> detail in the snow, or if it can just be "white" or if
> it can be blown out totally. (There is this
> false claim that Eskimos have 100 words for snow, which
> they don't... but skiers do and so do photographers! :-)
>
> And all of that has to be balanced against the
> brightness level for people's faces, black dogs, and
> white bears.
>
> >If I spot meter the black dog and the exposure meter
> >is centered the dog will be gray, so I use less exposure and it will
> >be darker.
>
> You guess at how much darker it should be...
>
> What a spot meter can show you (and a histogram can show
> even more easily), is how much of a range you have
> between the dog and whatever else there is. If it
> happens to be a snow bank, it might well be 7 or 8 stops
> difference and arbitarily adjusting the dog to something
> that "will be darker" will mean that you lose the
> texture of the snow. The trick is realizing that the
> dog is going to be off scale, so getting texture on both
> the snow and the dog means putting the snow right at the
> maximum. Then in post processing the brightness is
> adjusted to maintain the snow at just under maximum
> white while contrast is adjusted to bring the texture on
> the dog out of the black.
>
> It depends on the dynamic range of your camera of
> course, but the closer one puts the snow to maximum
> white the less noise will show up on the texture of the
> dog.
>
> --
> Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
> Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
| |
|
Porte Rouge <porterougeman@gmail.com> wrote:
>> So you take a wild guess at 1 or 2 stops more! Even
>> with film and no histograms most accomplished
>> photographers attempted to get within 1/2 a stop.
>> Today, with digital and histograms, it is entirely
>> possible to be within 1/3rd of a stop.
>
>Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
It's a wild guess.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
>> So you take a wild guess at 1 or 2 stops more! Even
>> with film and no histograms most accomplished
>> photographers attempted to get within 1/2 a stop.
>> Today, with digital and histograms, it is entirely
>> possible to be within 1/3rd of a stop.
>
>Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
It's a wild guess.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
| |
|
Porte Rouge wrote:
>> You are aware that ETTR is a two part process, part one
>> being boost the exposure to maximum possible, and part
>> two is to later reduce it to whatever it is that makes
>> your heart beat fast enough.
>>
>> You *have* to do both.
>>
>
> Yes, I understand. My question is, after ETTR what exactly do you
> yourself do in post processing. Do you adjust exposure, black point,
> or something else?
I adjust black point, which retains the highlights.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
>> You are aware that ETTR is a two part process, part one
>> being boost the exposure to maximum possible, and part
>> two is to later reduce it to whatever it is that makes
>> your heart beat fast enough.
>>
>> You *have* to do both.
>>
>
> Yes, I understand. My question is, after ETTR what exactly do you
> yourself do in post processing. Do you adjust exposure, black point,
> or something else?
I adjust black point, which retains the highlights.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^--------------------------------------------------- ------------
| |
|
On Oct 14, 11:56 pm, fl...@apaflo.com (Floyd L. Davidson) wrote:
> Porte Rouge <porterouge...@gmail.com> wrote:
> >> So you take a wild guess at 1 or 2 stops more! Even
> >> with film and no histograms most accomplished
> >> photographers attempted to get within 1/2 a stop.
> >> Today, with digital and histograms, it is entirely
> >> possible to be within 1/3rd of a stop.
>
> >Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
>
> It's a wild guess.
>
> --
> Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
> Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
Oh, well, that's too bad. I guess that's as far as we go, Floyd.
Thanks for answering my questions.
Porte
> Porte Rouge <porterouge...@gmail.com> wrote:
> >> So you take a wild guess at 1 or 2 stops more! Even
> >> with film and no histograms most accomplished
> >> photographers attempted to get within 1/2 a stop.
> >> Today, with digital and histograms, it is entirely
> >> possible to be within 1/3rd of a stop.
>
> >Floyd, baby, chill out. "Wild guess" is over the top. I'm a slow
>
> It's a wild guess.
>
> --
> Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
> Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
Oh, well, that's too bad. I guess that's as far as we go, Floyd.
Thanks for answering my questions.
Porte
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