Operation Photo Rescue's Online Community

OPR Workshop Information Exchange => General Techniques => Topic started by: Marydh on May 29, 2012, 04:19:01 PM

Title: Color correction
Post by: Marydh on May 29, 2012, 04:19:01 PM
I'm wondering what you guys do if after the levels and curve adjustments it still doesn't look right.
Do you fiddle around with hue/saturation and/or color balance?  I'm guessing that the original photo wasn't all that great to begin with, so in essence, you'd be changing the original.  Is that okay?
Thanks for your input.
Title: Re: Color correction
Post by: Mhayes on May 29, 2012, 04:32:04 PM
Mary, I usually start over and use a Curves Adjustment to find neutral gray. Jonas does some tweaking that is different than the Dave Cross way and he mentioned it some time back on that on another post. If that doesn't give me good colors, I probably will try to see if there is a reference photo for the color. For those too hosed up, the photo might have to go B/W. You can always try the hue/saturation or color balance if that helps. I notice that Kiska does a correction my going into Curves and tweaking each channel separate.

Title: Re: Color correction
Post by: glennab on May 29, 2012, 07:01:32 PM
Mary, Margie touched on a lot of things that I try, as well.  But I've discovered over the years that some  things that are unexpected will work at times.  I've had to start over with my color correction on several misbehaving images and used Shadows/Highlights and have been amazed at what that correction can do.  Hue/Saturation can sometimes tame an unruly color problem.  Sometimes I find that just bringing down the saturation helps with colors run amok when nothing else works. Other things to try are Selective Colors and Variations (which I don't see in CS5.  I don't know if they've moved or aren't there any more). Whether I use Levels or Curves, I always correct each channel separately.  And I try to use the eyedroppers to get the best results, unless the color is really bad to begin with.

Title: Re: Color correction
Post by: Marydh on May 30, 2012, 05:40:40 PM
Thanks Margie and Glennab for the tips.  I forgot about the shadow/highlights adjustment and it made quite a difference.  I'll work on trying to correct each channel in curves....not quite sure about that.
Title: Re: Color correction
Post by: Jonas.Wendorf on May 31, 2012, 12:14:28 PM
For the usual color cast it can also be a good idea to check colors for their plausibility.
E.g. finding red grass seems rather unrealistic, the same as an old woman with slightly green hair.
Judging from this you can also dedicate what other problems in the same tonality might look like, so if there's just one light source and you're correcting one part of the image, the other parts in the same tonality should be okay now.
Of course since we're not only dealing with color casts, but often with color reactions from disasters that can do horrendous things to color, usually some local adjustments will be needed as well. For this I mostly prefer masked curves (treating each channel individually to correct the color) or sometimes masked Selective Color / Hue/Saturation adj. layers since they allow finer control over the colors with built-in masking functionalities.

Also I recorded an action a while ago that works pretty good on correcting your usual color cast, but I haven't tested it on any OPR images so far.
Title: Re: Color correction
Post by: glennab on May 31, 2012, 01:09:15 PM
So, Jonas, you're saying that my green hair would throw off anyone's color correction?  Darn!

If you find that your action actually works on an OPR color cast, that would probably be an excellent tutorial to add to our collection.  Color casts seem to be one of the most problematic issues with our restorations. Especially if they're not consistent within one image.  I know that's knowledge that I'd appreciate adding to my arsenal!


Title: Re: Color correction
Post by: Jonas.Wendorf on May 31, 2012, 02:15:03 PM
Haha, only if it looks like chances are it might be green instead :-).
The action is pretty much an automated version of the neutral gray correction I posted earlier, if you want to, I'll write a short tutorial about it later :-).
Unfortunately this too doesn't work for multiple casts, but only for one "main" cast. For those cases you'll always need selections.