Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Bob Michaels"
<bob@b...> wrote:
> 
> I sent a 720 ppi file to my 1280 then resampled it to 360 and
printed
> it again. No difference to my naked eye, possible miniscule
> differences with a very good loupe but it's a hard call. 
> 
> It was a very sharp detailed 6x7 neg scanned at 3200 ppi in a
Minolta
> MultiPro.

Try resampling the 360ppi image back to 720ppi and then compare them
in Photoshop.  You may find that there's little if any difference, so
you wouldn't expect to see a difference in the print either.

Film scanners scan at a much higher resolution than the resolution you
can actually get out of film.   Many scanners can generate a 20
megapixel scan from 35mm film, but in real life you can get more
resolution out of a 6-megapixel digital SLR than from 35mm film in
most cases.  I've done experiments where I downsampled film scans to
1/4 their size and back up again and found very little difference. 
I've also upsampled 6-megapixel digital SLR files to 20 megapixel and
they had more detail than the 20-megapixel film scans.

It would make more sense to try the experiement with a true 720ppi
image from a digital SLR or with an artificially-generated
test image that clearly had 720ppi worth of detail.

--
Steve