Hello,
old thread, I know, but anyway:
I was using a 3170 Photo before I got a dedicated film scanner, and I've also done some more or less scientific 🙄 measures to see where it reaches its edge:
- scanned on highest res, and downsized to dpi-equivalents: 600, 800, 1000, 1200, 1400, 1600, 2400, 3200. Then upsized again to have a 300 dpi 8x12inch print and made the print (the scanned negative was very sharp). Result: clear differences between 600, 800 .. up to 1200, then just a very very tiny improvement on 1400, none on 1600 and above. Therefore I'd rate the real resolution around 1250 dpi.
- Scanned at highest res and then printed in 4x, 5x, 6x, 7x, 8x enlargement. Until 5x, I was rating the picture as 'very sharp' (of course you need to apply some usm to the scanned pictures, this might explain why some are very disappointed with their results), at 6x I could see a degradation of sharpness. Therefore I'd rate my 'eye sharpness' at 250 dpi.
Summary: for my eyesight the 3170 was very good until 5x enlargement, i.e. approximately 13x18cm print size (from 35mm negatives).
Regards,
Robert