Bill Cornett , Mar 03, 2004; 01:02 a.m.
Larry- I've shot art works up to eight by ten feet for catalogs, and the considerations are surprisingly similar to those where one is shooting copies of flat art the size of a standard sheet of paper. The trick is to have your light sources at precisely 45 degrees to the artwork, with the light coming from both sides of the subject. Another thing that will help is to use a polarizer.
With the bigger objects you will have to use more than one light per side to get things even. One rule of thumb is to have the lights at least 1.5 as far away from the subject as the subject is wide, as measured from the middle of the field of view. So if your subject is three feet wide, draw an imaginary line down the middle of it and set the lights at least 4.5 feet from that line--again, at a 45 degree angle. This should give you decently even coverage. Shadows are minimized by having the lights balanced as well as possible from either direction.
One problem I often ran into was the edges of metal frames giving me specular reflections. As always, for best results you should take the artworks out of the frames if you can.
Then again, I've had people claiming to get super results by taking flat art outside on a perfectly clear day and finding a good angle for the sunlight to hit it, which is usually 45 degrees. -Bill C.