It seems that everybody has an opinion on this, and I'm no exception. My comments are based on having a 2700 and 4000 pixels per inch 35mm film scanner, and comparing the results I've gotten from them. My answer is that 4000 is sometimes an improvement over 2700.
The sample pictures below are small bits of a scan at 2700 and 4000 pixels per inch, respectively. They have been enlarged. I think it's fairly easy to see the additional detail in the second image compared to the first. In particular, look at reflection on the left corner of the glasses.
This picture was taken on Kodak Supra 100, with a Nikon 50mm lens, on a tripod.
The pictures below, on the other hand, illustrate a case in which I think there is little if any extra detail captured by the higher resolution scan. Sure, you can see the grain better, but that's not useful image detail. This picture was taken on Kodak Supra 400, with an Olympus Stylus Epic, handheld.
I don't know why exactly the second picture wasn't sharp enough to benefit from the increased scanning resolution. I doubt it was the film, but I suspect the lens, autofocus sensor, or camera motion. If I ever care enough to control these variables to ascertain which are important, I'll update this page. Other related pages which you may find interesting are Robert Monaghan and R. N. Clark's.
For comparison, 4000 pixels per inch is 157 pixels per millimeter, or adequate to resolve approximately 80 lines per millimeter. 2700 pixels per inch is 106 pixels per millimeter, adequate to resolve 53 lines per millimeter. Thus, while there are certainly some combinations of film and equipment which can produce images sharp enough that the extra resolution is useful, it is not the case that all films and equipment will do this.
Copyright (C) 2010 by
Terran Melconian.
You may mirror this page for personal use. Images may be downloaded and
printed. All other rights reserved.