Shamroy on Shamroy
One difficulty in researching cinematography is that for the studio period especially there's not a lot of record of the aesthetic dimensions of the shooting process. Trade periodicals like American Cinematographer are invaluable, of course. (Incidentally one of the things I appreciated in Scott Higgins' book is his use of trade press as evidence without treating it as a transparent window into what the “industry” as a whole did or thought.) And there are a few scattered interviews and published accounts from cinematographers, or about them.
One useful account is Charles Higham's Hollywood Cameramen: Sources of Light (Indiana UP, 1970), a collection of interviews with seven cinematographers: Leon Shamroy, Lee Garmes, William Daniels, James Wong Howe, Stanley Cortez, Karl Straus, and Arthur Miller. These sketch in biographical details, but also give insight into their aesthetics. Shamroy for instance noted, "My signature became established as high-contrast: they'd always say, 'use more light,' but I liked shadows." (Higham 24). He elaborates on this under-lit style:
Zanuck gave me complete freedom at 20th... Here I developed my technique of using the absolute minimum of lights on a set.... To light economically is a rarity in this business: most cameramen put a light in front, others at the sides, fix up backlighting here and there; I don't. For instance, on Justine, in the scene with Michael York telephoning Justine in the bedroom, I only had one light shining on his face – to suggest dawn – and two other small lights. Every light has to mean something, be fully justified, like words in a sentence. (Higham 27-28).
And here he is on his approach to color:
I believe in accuracy; if you walk into a room with a candle flame, only the area round the flame should have warm colour; the rest of it should be cold. But Cukor [director of Justine] wanted the whole scene to be warm, through the use of coloured filters. I remember when I was making The Black Swan, I wanted to dispense with the usual Technicolor man from Kalmus, and to emulate the old master, men like Van Dyck and Rembrandt, and I'd say to Zanuck, 'When you're shooting a sunset, use yellow light instead of white light, and ignore realism, make a deliberate mistake.' And Mrs. Kalmus went to Zanuck and said, 'That isn't the way to make a colour picture should be photographed.' Zanuck stepped on me, but I was still the first black and white man to win an Oscar for colour – with that picture. (Higham 33-34).
I think “deliberate mistake” neatly summarizes Shamroy's approach.