|
Ant,
If I could offer an addendum ...
One thing that can bugger up the color of your photograph is the "white balance" setting on your camera. Check to see that the light hitting your painting is the same light your camera is expecting, such as: incandescent, flourescent, natural shade etc.
However, I'm not sure that I am getting to the core of your question.
Your camera's sensor will "meter" the light usually in one of three ways depending on how you've set it. There is "matrix," which is a total image calculus, a "center weighted," and a "spot" metering, which calculates it's exposure based on a small portion of the image that you have selected in your viewfinder.
If you introduce your arm into a "matrix" metering I think it would alter the calculus somewhat depending on how much of the frame you replace. This could alter the total image calculation / exposure such that the overall could look lighter or darker.
I would say that these meter calculations are basing their findings (exposure) more on light than color. This gets a little fuzzy. Whereas light reflects off of one color differently than another, but I think it's all about the amount of light and not color.
I hope I haven't muddied the water further.
__________________
Mike McCarty
|