Read a circa 70's interview that Peque Gallaga did with the late Conrado Baltazar for the defunct Ermita Magazine. At some point in the interview, he asked Baltazar bout Mike de Leon as cinematographer (at that time he just completed Maynila and Itim) and the man was totally impressed with his technique and style. His methodogy as DOP--well lit sets with LOTS of lights, doing tests shots and re-shooting if necessary, his experiments in processing etc.--are fascinating.
Just look at Maynila Sa Kuko, Kung Mangarap and, of course, Itim, and you'll see why.