In response to the excellent questions posed by friends who commented on my entry concerning "photographic ethics", I've been thinking hard about how adjustments made prior to the making of a photograph differ, if at all, from those made afterwards, whether in a darkroom or Photoshop.

As I noted in one reply, I can see all too readily how such a distinction would be susceptible to deconstructive critique. I use that term deliberately, since this separation of "before" and "after" strikes me as the sort of subtly ideological move that thinkers like Derrida were keen on interrogating, particularly in the aesthetic realm. Or, if you are of a more psychoanalytic bent, you could invoke the discussion of the "mirror stage", with its paradoxical temporality, to the same end. There is something inside us, whether imposed from without or arising from within, that wants to insist on the linear chronology that makes causality seem inevitable.

Nevertheless, alhough I can imagine how someone would dismantle my argument that what the photographer does prior to the act of recording the play of light is fundamentally different from what she or he does afterwards to make the resulting image presentable, I still feel that this distinction is right and, what is more, with the full moral force that word can bear.

I got out my copy of Walther Ruttman's 1927 documentary Berlin: Symphony of a Metropolis last night, a film of crucial importance for my intellectual development back in the early 1990s, and tried to see whether I could pinpoint what moves me about its "candid camera" shots of city life.

I decided that the truth I could impute to those images, my conviction that they captured aspects of Weimar Berlin as they appeared to the people who experienced them firsthand, mattered to me greatly. Recreations in this era of computer graphics run wild may be finely textured to the point where they look real. But knowing they aren't puts them in a different category.

I realize that this example confronts my dilemma obliquely, yet can't help but think that my sense of images from the increasingly distant past's truth is crucial to comprehending why I regard pre-photographic manipulation of focal plane, expopsure and frqaming differently than fixes and improvements undertaken after the documentary record has been established.