erik Not a great photo, but it's the only one I have at the moment (I can get a better one next week if that would help). There are three rows of IR lights are on the bottom of the metal slats under the black plastic, spaced about 1 inch apart in each row. Adjacent and parallel to them are visible light strips, so there are three rows of lights also spaced about 1 inch apart. The black plastic is to block out the overhead lights from above this setup, and the object to be photographed is placed on the wood below the lights (~1.5m away).
I was also looking back at a visible light only photo (no IR lighting) I took of the same setup, and it seems to have a similar effect?