USAF-1951 drum scanned?

[Pere Casals]

Where did you get your information that 8000 ppi is interpolated?

https://www.filmscanner.info/en/FilmscannerKlassen.html

See the "Drum scanner with photo multiplier technique" section. They say that the 1045ai can resolve around 6000dpi effective, but you have to scan at 12,000dpi nominal.

If you scan at 8000 then you get 4000 effective, which is an overkill anyway, usually, at least for LF or for regular films and lenses.

[calebarchie]

Where did you get your information that 8000 ppi is interpolated?

My bad I got mixed up with the 1015ai, looks like your scanner may need a thorough service.

[brbo]

Howtek 4500 (you need to click on images to see full res scans)...

4000dpi, 6m aperture:



4000dpi, 13m aperture:




2000dpi, 13m aperture:



You can clearly see the benefits of oversampling in the 4000dpi vs 2000dpi with 13m aperture. 13m aperture should, in theory, only allow 2000dpi, but since the readings at 4000dpi setting are taken at twice the rate of the 2000dpi you can get higher actual resolution. I guess that is how the Tangos get their smooth and yet detailed scans, deliberately selecting larger than optimal aperture.