Originally posted by rparmar In fact if you shoot in RAW you needn't wory at all about grey cards. Colour temperature can easily be fixed when you cook the RAW to PSD, JPG or whatever format you use.
I beg to disagree.
I realize that software these days are amazingly powerful, but nothing beats getting things right in the first place.
It is time consuming to fix WB in post-processing, and you need to have you computer monitor properly calibrated. Even then, it requires trained eyes. My wife is good at many things, fixing WB is not one of them. In particular, scenes with mixed lighting at times are nightmare to fix.
For important shots, a neutral gray card is always a good idea.