Mark Cassino <[EMAIL PROTECTED]> wrote: >As Ansel noted, how an image is rendered depends on three primary factors - >acutance (edge definition), resolution (the ability to render fine detail) >and grain (noise). The ideal photographic system would be high acutance, >high resolution and low noise. > >My working hypothesis is that while digital has lower resolution than film, >it has higher acutance and lower noise. Good film has superior resolution, >but seemingly lower acutance and higher noise levels. > >For a lot of subjects, the trade offs that come with digital work better >than those in film. It depends on the visual cues in the image that the >viewer picks up. My *ist-D came too late for me to do any bug macros, but I >expect that it will produce close ups of insects as good or better than the >best film. I say this in part because I've been able to get excellent >closeups using a 3.3 megapixel digtal up to this point. For that kind of >work, higher acutance (at the cost of resolution) works. If you think about >the visual cues that define a bug, it generally is about edges. I expect >the *ist-D to really rock with snowflakes this winter - because snowflakes >are nothing but edges. > >On the flip side, things that are visually defined more by textures than >edges seem to suffer in digital. I haven't tested it (hope to soon) but >things like a forest floor covered with dried leaves I expect will do >better with film. With my old CP990, that sort of stuff broke up and >started to look weird if I tried to enlarge the image. Film seemed to hold >up much better, and a larger format of film would have been much better >still. When you look closely at how something like that is recorded on >film, it's a whole bunch of gradients and no real hard edges. That's where >resolution really becomes important - and the complexity of the visual >pattern also minimizes the impact of the grain in film.
Great summary of the characteristics of film and digital, Mark! -- Mark Roberts Photography and writing www.robertstech.com
