[JoJo Gunn]

That question came up here:

http://www.freerepublic.com/focus/f-news/1062491/posts

For my part, no matter what they say, it makes sense to me to calibrate the camera(s) with standard gray scale and colors.

[Yeti]

For my part, no matter what they say, it makes sense to me to calibrate the camera(s) with standard gray scale and colors.

I think your right. I can think other ways, too, that are not "subjective," but objective methods in which one can some confidence about accuracy.