"Paul H." wrote in message
"Tom" wrote in message
ND filters eliminate or ameliorate overly-large discontinuities in contrast and will remain useful until digital cameras are capable
of
many
more bits per pixel than are current cameras.
Huh? This is just exactly backwards from what really happens. Large contrast values are MUCH easier to control when the exposure is spot
on…
which, of course, it can be when combining frames.
No, it’s not backwards–you just misunderstand. Bits-per-pixel is a
measure
of the brightness *range* encomposed by the camera’s sensor and A/D converters. Any photographer will tell you he’d rather have a RAW file at 48 bpp rather than 24 bpp any day; the greater the possible brightness range, the more one can do in post-processing.
Jeeze Paul, it is like we are on different planets here.
FORGET "brightness range" captured in ONE photograph. Let me give just one example and then I am passing on any further arguments. And yes, it is an extreme example, but here goes.
The photograph you have to take is of a welder practicing his/her trade in a dark, cavernous industrial workshop. The problem is to get as much detail of the entire scene as is possible to capture into one picture (not "one photoframe", one FINAL PICTURE).
Taking a series of shots, starting, say, with the proper exposure for the arc light itself and progressing into a series of long enough exposures to retreive surrounding workshop detail then combining these seperate frames into one picture is child’s play. Well, maybe an advanced child… but pretty easy nonetheless.
Then analyze these frames one by one. The first frame might just be a pinpoint of light showing detail only of the welding rod and a couple of inches surrounding the arc, the welder’s glove and hood. The rest of the frame is pitch black, but it DOES’NT MATTER. All that lost "brightness range" is going to be tossed out anyway.
Moving to the next frame, the arc is WAY overexposed but the welder and his immediate surroundings are properly exposed, yet no details show in either the arc or the workshop. You would throw out both the overexposed arc and the underexposed workshop from this frame and keep the welder.
Last frame, of course, has an exposure long enough to capture the workshop details although the welder and his/her arc is way overexposed. But once again, the overexposed portion is tossed and the properly exposed portion is kept. You STILL get ALL the "bits per pixel" possible to capture with any particular camera ->in the properly exposed portion of the frame<- which is all you are keeping anyway.
Again, the "bits per pixel" you keep are as good as is possible to capture for each SPECIFIC frame.
As for the ND filters, I was
referring to graduated ND for sunsets, etc. and I stand by my statement.
I knew the discussion included all ND’s and grads. And I still say they are not necessary.
Combining multiple images to create a single exposure is fine as long
as
you
don’t shoot trees and bushes when the wind is blowing, etc.
Once again Paul, there is a fundamental misunderstanding here of frame combining techniques. It does NOT MATTER if the trees move. As long as you have one frame with them properly exposed, the only motion shown would be what is there anyway, frame combining or not.
If they move during the portion of the shot used to capture, for example, the sky… it does not matter because the improperly exposed trees will not be seen in the final combined frame. Only the trees from the correctly exposed frame will be used, it doesn’t matter if a lumberjack comes along and cuts them all down in the interim. See?
I know how to layer frames just fine, thank you.
You are welcome, but nothing you have said here indicates you are capable of implementing this knowledge above a rudimentary level. This is not a condemnation of your intelligence, just a comment that you might be able to ratchet up your PS skills.
You just don’t seem to
appreciate how complex a scene can get when photographing landscapes and nature scenes.
Yes, I do. I also know how to control this complexity.
I don’t have the time or the patience to shoot ten frames to combine them later to make up a single shot.
Well, now we get to the rat killin’ (old Southern term). You have time to diddle with a bucketfull of filters, and accept their severe limitations as to composition, but don’t have time to bracket exposures? By the way, the only time I have ever used as many as ten frames for a scene, the scene was assembled as a mosiac, another version of "frame stacking".
Go here for mosaic examples from a real expert:
http://www.caldwellphotographic.com/StAugustineMosaics.htmlYeah, and I can get that
butterfly to beat her wings five or six times in succession, in exactly
the
same way, so I can get enough shots for later recombination.
And a ND or grad is going to be your salvation here? Baloney.
As long as you get ONE shot of the butterly correctly exposed, it does not matter if the damn insect then takes off and flies to Cleveland for the combined frames. They will all contain the properly exposed butterfly originally captured.
And, of
course, the flower she’s perched on is executing damped simple harmonic motion after being hit with a pulse of air and all I have to do is wait
for
just the right time in the decaying swing to snap my bracket shots. And hope the butterfly knows enough physics to beat her wings in the proper phase. Oh yeah, that’s do-able.
Yeah, those "butterfly filters" are the magic answer to all this. Who makes these things? Exactly how is a filter going to solve this problem? I have never seen a butterfly wing beat filter that, as you point out, "knows enough physics" to correct that action. My statement is that almost any shot that necessitates a ND or grad filter can be done with combined frames.
Do you even realize that when shooting across a field of grass, the wind blows differentially over distances of inches? And in a manner which doesn’t repeat? I don’t care how good you are with layers, that’s a
complex
scene and Photoshop layer combination is just not feasible under these circumstances.
Yes, they are. But that is not the question in this particular assertion, is it? You want to discuss inches while the only tool you bring to the table is a sledgehammer. I submit that if you allow yourself the indulgence of having the scene framing forced upon you by the filter you happen to have (that "moving grass" does not know that it can only "move" in the exact bottom half of the frame because that is the only grad you have), then it would do me no good to discuss layer masks, luminance masks, contrast masking and history brushes.
Once again, go to the page I referenced above. Examine the composits and see how motion is dealt with. And these are photomosaics, not even stacked images where motion can dissapear with the stroke of a history brush.
I do a lot of
nature/landscape photography and it’s a rare day when I can
successfully
bracket exposures with still-life precision.
No need to with "still life precision", but then I am never going to convince you of that.
Oh, for heaven’s sake: now you’re just being childish and rude, ignoring
my
"still-life" qualification. Of course I can bracket, but in nature photography wind, motion of scene elements, shadows, etc. often change so rapidly it is VERY difficult to get a set of exposures suitable for later combination into a single shot, assuming one wants a completed shot in a reasonable amount of time.
I will moderate my assertions, but would like to leave you with this… you REALLY need to get some better refined PhotoShop techniques mastered. Some of the things you are bringing to the table as arguments against frame combining techniques are just not applicable, such as the below…
Your vaunted "independent" scene element theory just isn’t realizable most of the time–what happens when the light undersides of leaves conflict in position/rotation with the darker tops in the same freaking exposure on the same tree?
…. See? You propose situations that even your use of filters cannot overcome. No ND or grad will solve this. No ND or grad can photograph both sides of the same leaf at the same time. You get ONE shot with the tree with the leaves up or down as may be the case. At some point, you have to say "the tree" is properly exposed, or as properly exposed as you can get it, no matter which side of the leaves show. Just as you would with filters.
These leaves are, of course,
attached by stems to the branch, lending another bit of complexity to have to work around if you don’t want the photo to look pasted together.
Which brings me yet again to PhotoShop expertise. If you can tell by looking at a photograph that PS manipulation has occured, then you are not looking at a professionally prepared photograph.
You have unreasonable expections concerning Photoshop.
No, I have quite reasonable expectations of PhotoShop. I expect it to replace ND filters, Graduated ND filters, and a host of other effect filters and it lives up to my expectations quite nicely.
It’s a great
program, but it isn’t a panacea and frame-combination is wonderful when it works, but it just isn’t practical to use a lot of the time.
I looked over ALL my posts and did not discover a single instance of my declaring PhotoShop a "panacea". This entire discussion was predicated on my assertion that PhotoShop could (and did, in my usage) replace ND and ND grad filters (especially grads, as there are still instances where a combination of frame stacking and ND’s might be useful, if not absolutely required).
Tom
