Hi Brian,
I agree about the need to control where the light goes, simply accomplished with something that casts a shadow on to the surfaces you don't need (read "want") lit.
I think I mentioned the concept of some bits of white and (for this use) black A4/Letter card, folded in half and opened to roughly 90 degrees, so they can be used as self supporting miniature "V flats". Oh dear, I also now remember that I may have suggested that I'd demonstrate such a concept in use (BTS) - and promptly forgot
I'll try to remember to do something tomorrow at work.
Dave