You have to adjust the curves individually. This may involve adjusting just one component or all three components in different amount. In the simplest case, if a photo has a blue cast, you can tweak the B(Blue) curve to reduce the amount the blue in the image.Originally Posted by wong1979
Of course it is best to get everything right in the first place. However there will be cases where you need to salvage a precious photo and this is where PSing comes to the rescue.Also, do you think it's a major doctoring or it's just minor one. Because, I too have noticed that by tweaking the RGB curve can improve ur pic tremendously. But then again, the purpose of photography is to present the best picture perfect pic? So if the original pic doesn't look right, that bit of PSing isn't that 'sinful' right?
Those who shoot in RAW can do such adjustment easily but if you know how to PS, almost anything can be corrected/slavaged/fixed. The question is if it is worth the time and effort to PS the photo. Sometimes it is easier just to go back and re-shoot but other times you can't so you have to salvaga the photo.