This is a question that i have posed to many people in the industry, yet no one has ever been able to answer it. I thought it was a relatively simple question, but apparently it is not.
Fact: If you throw a gray card into a shot, you can always get perfect white balance adjustment later by going into photoshop, selecting levels, clicking on the middle/neutral gray eyedropper, then sampling the grey card in the shot.
What I have been told is that if you're 18% gray is right, then there is absolutely no reason to adjust the white and black levels, again sampling off a kodak color separation guide that I also throw into every shot. (I do product photography.)
I have also been told that if your 18% gray is right, then all the colors will be right... in other words, you have now color corrected the shot.
Incidentally, I know people who sample the white, black, and gray in their shot in photoshop and say they need to do it get all the levels correct. Everytime I sample, in addition to gray, also the white and black levels, it ruins the picture in my opinion.
Relatedly, I still don't the understand the difference though between white balance, color temperature, and gray levels. It appears that if your white balance is correct, then the other two are also correct.
So, here's the question:
I process CMYK. I have a Kodak color separation guide in all my shots that shows the CMYK reference patches.
Isn't there a way in photoshop to click on those reference CMYK bars that appear in the shot (just like one does with neutral gray in the prior example), and be able to color correct all four CMYK channels, albeit one at a time.
I have asked so many people this question and no one seems to know how to do it. In fact, I've spent hours researching this, and the only answer I've received thus far is that, again, you don't have to do any CMYK adjustment as long as you've done your neutral gray adjustment.
Any help on this would be greatly appreciated.
Finally, is there an industry preference out there for digital camera color settings. Adobe II is what I've been told b/c it has a wider range than Adobe I or Ia, but to my eye Adobe II produces some very unnatural-looking colors, especially reds and blacks. I've always preferred Ia.
I photograph oriental rugs that appear in national ads and catalogs. Color is everything to me. If, in real life, I throw the ad on top of the rug, the colors need to be identical looking. And, even if they are identical, they also need to be have the same brightness and saturation, which is a whole other issue altogether.