Besides the great one about Jack Cardiff, there is:
"No Subtitles Necessary" (about Vilmos Zsigmond and Laszlo Kovacs)
"Painting with Light" (about Vittorio Storaro, made for U.K. television I think, only saw it once on Bravo or something...)
"James Wong Howe: Cinematographer" (I think this is now on the "Sweet Smell of Success" blu-ray from Criterion)
There is a South Bank Show episode about Freddie Young according to the internet.
I've heard there is a new documentary about Gabriel Figueroa.
"Light Keeps Me Company" (about Sven Nykvist) and "Tell Them Who You Are" (about Haskell Wexler) were made by their sons and covers more personal issues than just cinematography.
But "Visions of Light" is still the best cinematography documentary out there.