Luminosity problem

Jules wrote:

Hi everyone,
I’m currently editing this picture with photoshop 7.0 :
http://perso.wanadoo.fr/danieldubuisson/photoshop/lumiere_in egale.jpg
As you can see, it’s bright on the top and dark on the bottom. I’d like to equalize the luminosity/brightness of the picture, but without loosing the details on the bottom ( the leafy-like ornaments ). What can I do about it ?

Thanks
Jules

Play with the Burn Tool (set to ‘Highlights’) & the Dodge Tool (Set to ‘Shadows’) with Exposure set to a very low level. (5-15 %) , and use a rather big brush. Now you can darken the highlights without darkening the rest. And after that you can play with Levels to get the contrast you want.

Of course this could be done in much more difficult/efficient/better ways, but this is a simple way to get a fairly ok result in a minute.

HTH

Use brightness & contrast adjustment layer as shown: http://web.singnet.com.sg/~kcpps/01.jpg

"Jules" wrote in message

Hi everyone,
I’m currently editing this picture with photoshop 7.0 :
http://perso.wanadoo.fr/danieldubuisson/photoshop/lumiere_in egale.jpg
As you can see, it’s bright on the top and dark on the bottom. I’d like to equalize the luminosity/brightness of the picture, but without loosing the details on the bottom ( the leafy-like ornaments ). What can I do about it ?

Thanks
Jules

Your result looks perfect, but I don’t understand how you did it. Would you explain it to me, because I already tried to use this tool but it doesn’t work the way I want. ( the background’s luminosity is not equalized ).

Thanks a lot.
Jules.

"kctan" a

Select the area you want to lighten with Rectangular Marquee Tool then go to Layer> New Adjustment Layer> Brightness/Contrast… and click OK. Drag the levels (brightness & contrast) to match the bottom tone to upper tone. You will see sharp line due to selection with bright tone at the center but not to worry. Select Brush Tool and blend those tones by brushing with the combination of appropriate brush size, pressure and hardness. I prefer ‘0’ hardness and 30% pressure. The trick is brushing with the appropriate foreground color setting on the tool palette. Black to darken (back to unadjusted level}and white to the adjusted level. Toggle the foreground color to blend. Hope you understand me 🙂

"Jules" wrote in message

Your result looks perfect, but I don’t understand how you did it. Would you explain it to me, because I already tried to use this tool but it
doesn’t work the way I want. ( the background’s luminosity is not equalized ).

Thanks a lot.
Jules.

"kctan" a

In article <do6t2l$k0a$>,
"kctan" wrote:

Select the area you want to lighten with Rectangular Marquee Tool then go to Layer> New Adjustment Layer> Brightness/Contrast… and click OK.

I recommend that you do not do this.

Instead, select the areas and use Layer->New Adjustment Layer->Curves.

The Brightness/Contrast command degrades the quality of an image, because it is a "linear" command that removes detail from the hilights and/or shadows.

Everything you can do with Brightness/Contrast, you can also do with Curves–but Curves does not degrade the quality of the image by clipping hilight and shadow detail.

Brightness/Contrast is inherently destructive. Once you learn how to use Curves, you will never go back.

—
Art, photography, shareware, polyamory, literature, kink: all at http://www.xeromag.com/franklin.html

Thanks for the kind reminder 🙂 It’s true that curves won’t clip highlight & shadow but I prefer levels as I can see both the highlight & shadow cut off points. I use curves only when the RGB contrast are mismatched. For image with limited tones (like this one got only black on yellow), brightness/contrast will do and straight forwards. Why use an axe to chop an apple when you got a knife?

http://web.singnet.com.sg/~kcpps

"tacit" wrote in message

In article <do6t2l$k0a$>,
"kctan" wrote:

Select the area you want to lighten with Rectangular Marquee Tool then go to
Layer> New Adjustment Layer> Brightness/Contrast… and click OK.

I recommend that you do not do this.

Instead, select the areas and use Layer->New Adjustment Layer->Curves.
The Brightness/Contrast command degrades the quality of an image, because it is a "linear" command that removes detail from the hilights and/or shadows.

Everything you can do with Brightness/Contrast, you can also do with Curves–but Curves does not degrade the quality of the image by clipping hilight and shadow detail.

Brightness/Contrast is inherently destructive. Once you learn how to use Curves, you will never go back.

—
Art, photography, shareware, polyamory, literature, kink: all at http://www.xeromag.com/franklin.html

"kctan" wrote in message

Thanks for the kind reminder 🙂 It’s true that curves won’t clip highlight & shadow but I prefer levels as I can see both the highlight & shadow cut off points. I use curves only when the RGB contrast are mismatched. For image with limited tones (like this one got only black on yellow), brightness/contrast will do and straight forwards. Why use an axe to chop an apple when you got a knife?

I’m with tacit on this one. Although I would not recommend that you abandon levels, you have already recognized that there are occasional problem images where curves provides a better solution.

I think there may be additional situations where curves may improve things as well – for example setting a shadow, highlight, and neutral is usually (not always) possible with levels. Add a skin tone or other important color to the mix, or a mixture or light and dark objects whose contrast you want to enhance, and you are in curve territory.

I think of curves as being no more powerful than levels, just much more finely divided. Why use a knife (levels) to cut a loaf of bread (fix your colors) when you already paid for a bread slicing machine (curves). —

Mike Russell
www.curvemeister.com

Mike Russell wrote:

"kctan" wrote in message

Thanks for the kind reminder 🙂 It’s true that curves won’t clip highlight & shadow but I prefer levels as I can see both the highlight & shadow cut off points. I use curves only when the RGB contrast are mismatched. For image with limited tones (like this one got only black on yellow), brightness/contrast will do and straight forwards. Why use an axe to chop an apple when you got a knife?

I’m with tacit on this one. Although I would not recommend that you abandon levels, you have already recognized that there are occasional problem images where curves provides a better solution.

I think there may be additional situations where curves may improve things as well – for example setting a shadow, highlight, and neutral is usually (not always) possible with levels. Add a skin tone or other important color to the mix, or a mixture or light and dark objects whose contrast you want to enhance, and you are in curve territory.

I think of curves as being no more powerful than levels, just much more finely divided. Why use a knife (levels) to cut a loaf of bread (fix your colors) when you already paid for a bread slicing machine (curves).

I would love to learn to work with Curves, but I’m still a bit afraid of the ‘bread slicing machine’. It just cuts too fast for me. 🙂 But I took the big step and learned to work with the Pen Too tool, so I guess It’s time now to check the Curvemeister….

"Trace Elliot" wrote in message
news:cc1a0$43a7ba59$3e3be867

I would love to learn to work with Curves, but I’m still a bit afraid of the ‘bread slicing machine’. It just cuts too fast for me. 🙂 But I took the big step and learned to work with the Pen Too tool, so I guess It’s time now to check the Curvemeister….

Well, as it happens, the next Curvemeister class starts January 1. You would need access to a windows system with Photoshop or Elements to use the curvemeister demo.

The principles that you get from the class: including shadow, highlight, neutral, and flesh tones can be used with Photoshop’s curves. —

Mike Russell
www.curvemeister.com

Well, I would like to thank all of you for your kind answers and suggestions.
I’ll try to translate all of them in the french version of photoshop and use them.
Those answers look acute and appropriate to my problem.

Thanks a lot
Jules

"Jules" wrote in message

Well, I would like to thank all of you for your kind answers and suggestions. I’ll try to translate all of them in the french version of photoshop and use them.
Those answers look acute and appropriate to my problem.

Looking back over this thread, I see that my contribution was not really relevant to Jules’s original question. In honor of the Christmas holiday, I would like to make another attempt.

1) duplicate the image to a new layer.

2) run Filter>Other>Maximize with the radius set to 7.

3) run Filter>Blur>Gaussian blur with the radius set to 35. This creates an image that more or less reflects the overall brightness of the paper, minus the black lines.

3) set the mode of the new layer to "Linear Dodge". This removes most of the variation in the paper color.

4) If you want to recreate the original line art, Add a Levels adjustment layer above the Linear Dodge layer. Set the black triangle to 30 and the white triangle to 209. There is no advantage to using curves in this situation, and Levels has the advantage that the histogram clearly indicates the paper and ink pixel values..

The result after step 4 will be very close to a clean black on white image of the original. If you want to retain some of the texture of the original paper, reduce the transparency of the Levels layer.

There are many tiny yellow patches on the white paper. These are due to a dark blue channel in the original image, as often happens under relatively dim tungsten light. One way to remove the patches is to replace the blue channel with the green one.
—
Mike Russell
www.curvemeister.com

In my previous post – add an Image>Adjustments>Invert to the end of step 3.

—

Mike Russell
www.curvemeister.com

You have misunderstood me. No argument that curves is the most powerful image adjustment tool above all but not necessary to use it at all time. I’d been manipulating image’s slopes in the color separation process for many years correcting curves or slopes for faithful colors. It is fortunate now that with the digital technology, we can choose the image adjustment tool according to situation and not just on one that may confuse the beginner. That why PS has so many adjustment tools for you to select appropriately. When the RGB tones curves are in order or parallel while adjustments are on color cast, luminance and contrast only, levels are sufficient. If only on just color casts, use the color balances or the variations tool. If your image is graphic one with just several tones but lack luminance, then brightness/contrast is the one. If the image RGB slopes are mismatched (unparallel or color failure), then only curves adjustments can rectify the situation. But never forget the selective color because it is as powerful as slope adjustment but check with histogram to make sure no clipping of highlight and shadow tones. If you understand all the tone adjustments’ functions, a combined manipulations by the experiences will produce faster and better result than just using curves alone. More importantly is to get a pleasing result 🙂

"Mike Russell" wrote in message

"kctan" wrote in message

Thanks for the kind reminder 🙂 It’s true that curves won’t clip highlight & shadow but I prefer levels as I can see both the highlight & shadow cut off points. I use curves only when the RGB contrast are mismatched. For image with limited tones (like this one got only black on yellow), brightness/contrast will do and straight forwards. Why use an axe to chop an apple when you got a knife?

I’m with tacit on this one. Although I would not recommend that you abandon levels, you have already recognized that there are occasional problem images where curves provides a better solution.

I think there may be additional situations where curves may improve things as well – for example setting a shadow, highlight, and neutral is usually (not always) possible with levels. Add a skin tone or other important color to the mix, or a mixture or light and dark objects whose contrast you want to enhance, and you are in curve territory.

I think of curves as being no more powerful than levels, just much more finely divided. Why use a knife (levels) to cut a loaf of bread (fix your colors) when you already paid for a bread slicing machine (curves). —

Mike Russell
www.curvemeister.com

Mike Russell wrote:

Well, as it happens, the next
Curvemeister class starts January 1.
You would need access to a windows
system with Photoshop or Elements to
use the curvemeister demo.

The principles that you get from the
class: including shadow, highlight,
neutral, and flesh tones can be used
with Photoshop’s curves.
—
Mike Russell
www.curvemeister.com

Mike, I have a comment and a question.

Comment: I have been lurking here for just a few weeks, with an occasional comment. Your posts are the most enlightening and straight forward of any I have seen. I appreciate your common sense approach to answering people.

Question: Would you be so kind as to enlighten me (us) further about the Curvemeister class in January. What are the logistics, etc?

Thanks and cheers, Lee O.

"Lee O." wrote in message news:22771-43A844AA- ….

Mike, I have a comment and a question.

Comment: I have been lurking here for just a few weeks, with an occasional comment. Your posts are the most enlightening and straight forward of any I have seen. I appreciate your common sense approach to answering people.

Thanks, Lee. Most responses, mine included, go unanswered. So comments like this are much appreciated.

Question: Would you be so kind as to enlighten me (us) further about the Curvemeister class in January. What are the logistics, etc?

Here’s a more detailed description of the class:
http://www.curvemeister.com/support/class/index.htm
—

Mike Russell
www.curvemeister.com