Thanks Charles, always nice to get such comments from an expert.
Barry: thanks.
I'm not 100% certain that I understand your question.
I use flash and set the white balance on the camera (mostly Nikon D90) for flash, I don't actually use a gray card to preset the WB.
I use a gray card for almost all my backgrounds.
However, I don't bother to make the background the same intensity of gray between images. Thus some images may have a dark gray and some may be almost white background, but they all come from the same gray card.
The only consistency is that the RGB content are equal although I often get sloppy and get the RGB values close but not perfectly matched; also the intensity of gray often varies within an image.
Thus the top part of the background could have RGB values of 240 240 240 (or more likely 238 240 242) and the bottom part 220 220 220. This result is because most of the light comes in from the top and thus the bottom part of the image is darker than the top part.
Black is simply RGB values of 0 0 0 , white is 255 255 255 and mid gray is 128 128 128.
I adjust the intensity of gray using the curves feature in Photoshop.
For plates, i.e., more than 1 image in a set I try to get all the backgrounds to look the same intensity of gray.
SEE HERE
I take more care with printed images than with images to be displayed on a monitor.
Hope this helps.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
