This latest and largest collection of interviews with photographers, drawn from the European magazine Camera, raises the question of why they, more than artists or writers or other creative types, are regularly asked to account for themselves. Here, responding to routine queries (of the ""How did you get started in photography?"" ilk) that are seldom followed through, such luminaries as Paul Strand, Man Ray, Kertesz, Lartigue, Cartier-Bresson, and Eugene Smith supply information familiar to anyone who's read about them; they've told it all before, they're not challenged--or even discerningly approached. (""That is a more pompous way than I would put it,"" Smith replies to a suggestion that his pictures have ""the power of transcendence."") But the prompting does elicit some vivid comments (Imogene Cunningham on mass-portraitist August Sander: ""that man didn't know the good from the bad""), some historical emendations and amplifications (Herbert Bayer on the Bauhaus and 1930s Berlin, ""the world city""; Henry Holmes-Smith on the New Bauhaus; George Rodger on the beginning of Magnum). And both Wynn Bullock and Minor White are provocative on the subject of teaching photography (a pointless pursuit, according to other respondents). But the standouts are those who, invited to speak, simply tell their own story--projecting a personality (as loitering-Parisian Robert Doisneau does, disarmingly) or putting a public career on record. Historian Helmut Gernsheim's self-congratulatory account of his collecting and connoisseurship coups is insufferable--and nonetheless engrossing (Julia Margaret Cameron's celebrated profile of Mrs. Duckworth was a bargain--the vendor didn't know she was the second Mrs. Leslie Stephen, mother of V. Woolf). Beaumont Newhall's recollections of first exhibiting photographs at the Museum of Modern Art and getting George Eastman House in shape are basic history, however flat. Some are duds, some are intermittently rewarding, a few are diamonds in the rough--but there's ho dialogue anywhere.