The 2720S will provide scans that are at least as sharp, if not even a bit
more sharp, than the 4490 when it comes to 35 mm. This sharpness will be
even more important with the small instamatic format and the 4490 will not
come with a holder for that format. The 4490 will allow you to scan medium
format and does have ICE though (not sure if those capabilities are
important to you). Can't you get an adapter for less than 80 pounds via
ebay? I would be tempted to go with the adpater and current scanner IF IF
IF you are sure the Mac drivers and software are decent for this scanner.
Doug
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www.BetterScanning.com - Custom Film Holders and Accessories for Agfa,
Microtek and Epson Scanners