There are already two questions on how to make a gray card, but unfortunately my ignorance goes deeper than that. How do you use a gray card?
I have heard about 18% gray tone — what is it really, and why 18% (and not 20% or some other value), and how can I make it in Photoshop?
I know that there are "gray cards" sold that help with exposure/color correction, but as I'm on a tight budget I'd like to make my own. Is this possible? Also, are there other objects (paint sample ...
I read an article called Expose (to the) Right, which explained why you should try to get the graph of the histogram as much to the right of the scale as possible. The reasoning is that DSLRs record ...
Do I have to have the gray card on a specific angle while taking a photo for custom white balance calibration? Or it is irrelevant? I am guessing that the gray card plane should be perpendicular (90 ...
I know 18% grey cards are supposed to provide a neutral color to set custom white balance. But why are grey cards used instead of pure white ones? My assumptions: Is a specific greytone easier to ...
I know that a real gray card is the best thing to use to determine exposure. But I'd like to know if there are other naturally available features that can be used in a quick and dirty way. Are fields ...
In a comment to my answer on gray card angles, @underarock mentioned having used several gray card shots at different angles to cope better with metamerism. This sounds intriguing, but I'm still not ...