Using Channel Mixer Effectively

[abdul10000]

The channel mixer is truly wonderful in adding details to burned channels (in portraits its the red channel usually).

The problem is that when using the green channel to boost detail in the red channel, the overall color of the skin changes from natural red-pink to grayish yellow. No color adjustment after wards seem to correct this problem.

Did you ever run into this kind of problem and if so how did you solve it?


Thanks in advance!


edit: forgot to add I set the channel mixer layer adjustment to luminosity and in the layer blending options I limit the adjustment to the red channel only by deselecting the green and blue channels.

[pixelzombie]

i sometimes have to make a new channel using calculations when channel mixer doesn't give the right look and then bring that new channel to its own layer...

[byRo]

Originally Posted by abdul10000

......I set the channel mixer layer adjustment to luminosity and in the layer blending options I limit the adjustment to the red channel only by deselecting the green and blue channels.

?
Seems tome that if you are deselecting the green and blue channels of the channel mixer, that would defeat the reason for setting the blending to luminosity.
?

Agree with the rest though, channel mixing is a good way to vary the skin texture.

Rô

[abdul10000]

Originally Posted by byRo

?
Seems tome that if you are deselecting the green and blue channels of the channel mixer, that would defeat the reason for setting the blending to luminosity.
?

Agree with the rest though, channel mixing is a good way to vary the skin texture.

Rô

got you, but if you do not limit the adjustment to the red channel the green and blue channels will become darker and more contrasty.

What is your solution for that problem? Counter the problem by increasing brightness with a curves adjustment for example?

Thanks

[byRo]

Originally Posted by abdul10000

What is your solution for that problem? Counter the problem by increasing brightness with a curves adjustment for example?

If you are setting a layer's blending to luminosity, then the layer has basically just turned into a greyscale.
Thinking like that then you could use the monochrome option of the channel mixer - that way you don't have to adjust the three channels

- or -

(Much easier) Use a "Colour Balance" layer instead of the channel mixer. That way you don't have to worry (much*) about getting the sums right - and as a bonus you can adjust highlight / mid / shadows separately.

(* this adjustment layer isn't exactly "linear" and the "preserve luminosity" option often does exactly the opposite )

Rô