Channel Desaturation

[pantoned]

Hi, I usually use alienskin exposure to quickly make photos look like polaroids, etc.. but the problem is that the plugin creates a flattened image on top of the multi-layer file and it doesn't allow later retouching, so I tought I could translate the plugin parameters to adjustment layers, a curve for the tone, a photo filter to give a cast but then there is a saturation controls where they change the saturation in every rgb channel, how can I do this with photoshop? I've tried with the channel mixer in saturation mode but its not this, the problem is that I don't understand how does saturation really work in photoshop, it lightens and darkens some parts of the image that's for sure, but I don't get how.

Any help would be appreciated. There must be an easy way to do it right?

Arnau.

[philbach]

Perhaps this is not the correct answer, but all you have to do is add a HSL adjustment layer to the stack.

[pantoned]

thanks but hue-saturation doesn't allow to apply saturation to just one channel, you can touch either master or selective colors, but not channels (at least I'm not aware of the way to do it).

Arnau

Originally Posted by philbach

Perhaps this is not the correct answer, but all you have to do is add a HSL adjustment layer to the stack.

[DiamondsDr47]

There is blending option to apply the effect...

[pantoned]

Thanks very much for your reply, I've forgotten about the blending options, I was sure this would do it but I tried it with three pure rgb color bars and it doesn't work... I thinks i'm just trying to do something impossible, I mean I think for the saturation to work it needs to change brightness in all three channels. Anyway it gets close enought to what I'm looking for so I won't keep searching for alternatives.

Arnau.

Originally Posted by DiamondsDr47

There is blending option to apply the effect...

[Swampy]

If you have CS3, check out the Black/White adjustment layer. If you set it for luminosity blend mode before applying the sliders you can work in the color channels. I have a video tutorial on it showing how to use it to mask dificult treeline/sky selections, but you may get some ideas if you watch the video. See the link to my tutorials in my signature below.

[Richard Quindry]

If you set up Adobe Camera Raw to open jpgs and tiffs (there seems to currently to be a bug in this with tiffs - you may have to change your file extension from .tif to .tiff) you can then apply very fine tuned hue/saturation/lightness controls to many colors at once.

Another possibility is converting the image to LAB and adjusting the a and b channels with a curves adjustment layer.

Rich Quindry www.Quindry.com