Steven Desjardins mused: > > I remember when folks were estimating 20-30 MP for full equivalency. . . So do I. Maybe it's because I was one of those folks. I came up with that figure based on my own experience with scanning Provia & Velvia; there was obviously more real resolution available from a 4000 ppi scan than from one at 2700; I estimated that the best film scanners might get 5000 ppi of real resolution out of an image under optimal conditions. That (4000 - 5000 ppi) corresponds to te 20-30 MP figure given above. > And, of course, the 6 MP cameras work well enough for many folks since > many did not take full advantage of the resolution available in 35 mm.
Quite. A 6MP camera is only a factor of two shy of a 24MP image when it comes to resolution, and it's quite easy for other factors to far outweigh the resolution of the sensor when it comes to image capture. Basically, unless you're using a good prime lens and a rigid camera support, and photographing high-contrast subjects, you're not going to get anywhere near the physical limits. On a practical level, 6MP is enough for a full-frame 8x10 at 300 ppi, or a moderately cropped image at 200 ppi. That's good enough for all but the most exacting uses. And finally, as others have pointed out, resolution isn't everything. THe smoothness and lack of grain from digital images works in their favour. It's also far too easy to have colour balance and saturation problems introduced at the scanning stage - the direct capture in a digital camera eliminates that step. When I first started scanning and printing my images I decided that a 4MP camera represented the line in the sand for my purposes. I didn't quite manage to hold out that long - the realities of a forthcoming European vacation made a 3.3MP camera in the hand a better choice than a 4MP camera to be released some time in the future. I'd have bought a Pentax DSLR with a 4MP sensor if one had been released.
