Yellow/red cast

[Angel_Ice]

Originally Posted by philbach

Hi Angel Ice.
Lab mode is a different way of expressing color. We usually use RGB Mode for most of our work (Red, Green, &Blue) or CYMK Mode which is used for printing. Lab uses Lightnes and A & B channels. Before using Lab mode though its a good idea to have a good understanding of RGB and photoshop.

The advantage of Lab is that one can alter color without affecting luminosity or vice versa.

I am not a LAB expert. I read Dan Margulis "Photoshop Lab Color" last fall for the first time and I plan on reading it again this fall too. Its an excellent book, but for me I need to read it a few times to understand it better.

Thanks so much for this explanation, it's more understable for me that the one found in the Adobe Help file; thanks Flora for coping and pasting the Adobe Help but i have red it before and it was not clear for me.

Do you have some exemple of this technique or i'm going OT here?

[philbach]

Well using the above photo; open it in photoshop and then convert from RGB to LAB mode. In lab open up a curves adjustment layer. When the curves dialog box comes up I started with the A channel (Magenta and Green). I then rotated the diagonal line clockwise to desaturate the Magenta and greens. After doing this go to the b channel to desaturate the Blue and Yellow.

Again there are other ways of dealing with oversaturation. Using Lab is an excellent way to deal with color problems. I wish I knew more about using it.