
Originally Posted by
TheMightyZog
Yes, in some cases, rgb channels can help manipulate/correct images much better than curves or levels.
Basically you can apply the individual channels to other channels or the rgb master to effect parts of the image which are impossible to change by curves - in fact it is such a useful technique I think I'll write a page on it for my web site (have a look next week). I think it is much easier to start with the Lab colour space, as it separates tones from colours (whereas rgb has both in each channel).
If you are really want to learn about it then read books by Dan Margulis - he is the guru of colour correction. But beware you have to read this books about 3 times to fully understand what can be done! I've tried summarising a few of them on my web site.