I snatched this from the site for the the Stanley Kubrick Exhibition. http://www.stanleykubrick.de

The caption underneath it said: "Stanley Kubrick and Geoffrey Unsworth developed a system for calculating from the grey tones of b/w Polaroids the right lighting for filming 2001: A SPACE ODYSSEY."

In the bottom image, that appears to be Kubrick talking to Keir Dullea (or his stand-in).