The most important ‘number’ regarding a scanned image is the overall file size (expressed as Mb). The next most important detail is the quality of the optical system used to scan. For instance - digital cameras are normally compared in terms of both its Mb size and the lens that comes with it, not the resolution of the files it produces!

The dpi of an image by itself has no real bearing on image quality because it represents only part of the story.

Scanning should always be done at a dpi setting that is appropriate to the required file size. There can be some benefits to scanning all film at the highest possible resolution but in the end the file size must be suitable for the purpose for which it is needed: there is no point making a 16-bit 200Mb file if all that is needed is a 5x7 print.

Our own digital print equipment, supplied by the industry leader, Noritsu, decided some time ago to automatically scan film with a resolution appropriate to the end use. One of their engineers apparently decided it would be a good idea to save the image file at 72 dpi , presumably because it matched the format for a computer’s monitor. We concede this is a nuisance because it means the dimension and dpi may need be adjusted to suit other applications. Oh well, if they had chosen 300 dpi then we’d all be happy apart from the people who want 200dpi, or 4000dpi or 248dpi.....