wrote:
When a skin tone is in natural light, correcting it by the numbers is fairly easy. But if the skin tone is in shade (e.g. back lit), are there any good tricks?
The important thing to keep in mind when adjusting a skin tone is to get the hue and saturation where they need to be, and adjust the brightness. Although some amount of blue is expected in a shadow, in general it’s best to shoot for a full skin tone, and vary the brightness only with the shadow.
Adjustments like this are generally tricky in RGB, since adjusting hue and saturation separately is difficult. Although the RGB master curve is sometimes useful, it has the problem that it alters hue, and does not apply the same brightness change to different hues. For this reason, Lab is often an easier color space in which to remove an overall color cast. By the same token, RGB is better for removing a cast that is associated with a shadow. —
Mike Russell
www.curvemeister.com