Neeper wrote:I usually desaturate and use the history tool. Am I doing it wrong?
No, I wouldn't say that there's a wrong way to do it. I think it might just give different results.
I used to desaturate, but I've read, and since found for myself, that when you use the channel mixer, you can fine tune more and better mix the contrast between light and dark, depending on how you mix the channels together. By using the channel mixer, you are manipulating how each colour channel in the picture is desaturated (turned to grey/B&W), whereas desaturating "generally", flattens all the colours to grey using the same amount.
Clear as mud ?? I guess it depends on what look you want.
For example:
Below is the same picture, 1st with the green bias (as the original above) and the 2nd is red bias. The 3rd is simply desaturated.
Green=90%, Red=10%
Red=90%, Green=10%
Desaturated
Notice how in the green bias, the foliage in the bottom right hand corner is in better contrast to it's background, where as the red bias tends to lose this to the background. The desaturated one is similar to the red bias, for the foliage, but the OOF daisies in the background are much darker, compared to either of the versions changed with the channel mixer.
Hope this explains a little of my thought process....?!?
Aussie Dave