Overexposure/Underexposure Correction Options?

cerement

Yeah, yeah, yeah, I know, shoulda shot correctly in the first place, but anyways ... and my camera doesn't do RAW, so hush you ...

What are people's opinions on the different techniques to correct for overexposure/underexposure in Photoshop CS2? Basically looking for what people with a better eye than me think gives better or smoother or more "realistic" results on a consistent basis. Have tried all of the following and lots of hide/show layer to the point I'm getting cross-eyed trying to compare the options. Generally like to work in LAB for no other reason than to avoid color shifting and like to work with correction layers to be able to fade or blend the results as need be.

1) Image -> Adjustments -> Shadow/Highlight in Advanced mode

2) Contrast Masking -- http://luminous-landscape.com/tutorials/contrast_masking.shtml -- can leave large glowing halos if not careful

3) Image -> Adjustments -> Exposure -- RGB only, seems to work in "sledgehammer" mode only

4) Dupe layer set to Multiply or Screen blending mode -- most referenced pre-Shadow/Highlight availability

5) Curves adjustment layers only

6) Any others?

Thanks in advance for everyone's opinions!

ratcheer

I have been pretty satisfied with contrast masking and I have not noticed the large halos. But, I am pretty much a beginner. Maybe I need to look at my results more closely.

Here is an example I did a couple of weeks ago. The original was very underexposed.

I suppose there is a bit of an aura around the pine tree's needles.

Tim

PS - Let me say that this photo was not taken by me. It was posted on another forum asking for advice on editing for better exposure. If I should remove this post for that reason, please let me know and I will understand.

cerement

Here's a visual comparison of the three methods I like the best. All just coarse corrections, generally will need some saturation and minor curve touches.

Before:


After - using Contrast Masking:


After - using Shadow/Highlight:


After - using copied layer in Screen blend:

BinaryFx

cerement wrote:

Have tried all of the following and lots of hide/show layer to the point I'm getting cross-eyed trying to compare the options.

Hi cerement, haha, yes - as with sharpening, too many variables for automated push button solutions and it often comes down to subjective personal taste. I like actions to automate the tedious stage of building the various methods, then it is just a "simple" matter of clicking through the various history snapshots that the action saves to find the "best" result for that image.

Generally like to work in LAB for no other reason than to avoid color shifting and like to work with correction layers to be able to fade or blend the results as need be.

One can work in color, hue, saturation or luminance blend modes in RGB and CMYK which isolate colour and or tone (not the same as LAB but similar in that unlike normal blend mode in RGB and CMYK, colour and tone are treated separate). This is often more critical in CMYK work where one is more concerned about colour mode changes than in RGB. For example, in RGB, one can sharpen a layer blended in luminosity blend mode (or fade if not using layers). This will not itroduce colour shifts (but it is not the same as L of LAB, even though both isolate colour from tone).

Back to the general part of your original post...

The methods that you have been discussing are for processed images, in a RGB*, non linear gamma encoded space such as sRGB, Adobe RGB etc. (*Also obviously applies to Grayscale, CMYK and LAB)

What options do Camera RAW file format users have?

RawShooter Essentials (MS Win only, get it now for free before it disappears!) and RawShooter Premium (commercial, see below**) offer a "Fill Light" option that seems to have similar results:

http://www.pixmantec.com/

**This company has recently been acquired by Adobe, so we can hopefully expect to see some integration [12.5 mb podcast] of these Pixmantec features into future versions of Adobe Lightroom and or Adobe Camera Raw. It is great to see that this area of image enhancement is being made available to linear RAW data as well as in post processing on the final rendered image.

Another approach for those without suitable image editing software or skills can be found here (still appears to be in beta as a limited web service):

http://www.shadowilluminator.org/


Best,

Stephen Marsh
http://members.ozemail.com.au/~binaryfx/

cerement

BinaryFx wrote:

Another approach for those without suitable image editing software or skills can be found here (still appears to be in beta as a limited web service):
http://www.shadowilluminator.org/

From what I can see from their online sample, from 1) the amount of lightening of the background, and 2) that it's an online service, it very much looks like they're just running the picture through the equivalent of Shadow/Highlight in GIMP ;P

My punishment for not keeping control of my camera is having the trip tour leader be helpful and take some snapshots for me. Under normal conditions, I would dump most of these except the girl pictured would like a copy to prove to her family how brave she was ;P