Perfectly Even Copy Lighting - Page 2
Set your lights for a traditional copy setup and place the artwork to be copied in front of the camera. Using a light meter, try and obtain relatively even illumination. It is not necessary to be exact. Frame the artwork in the viewfinder.
Remove the artwork and substitute a sheet of white paper that is large enough to cover the complete viewfinder or artwork. It is important that this paper is clean and does not have significant texture as it is going to capture the areas of fall-off.Set your exposure so that the brightest part of the frame is close to 255, but not actually at this brightness. Capture an image and save it. It is important to ensure that the lighting, white balance or any other variable are not changed before photographing the artwork.
I have provided RGB values for the left and right side of the frame to illustrate the falloff in the intensity of the lighting from the left to right side. With a two light copy setup you could normally get more even lighting than this, but this exaggeration is useful to show the technique. The black keyline around the photo has been added for illustrative purposes.