On 2015-05-24 05:36, Phillip Helbig (undress to reply) wrote:
Now that I photograph exclusively digitally (Pentax K10D and Ricoh GR),
of course I have all the pictures as JPEG files (and RAW as well from
the K10D). I got the K10D in 2008. From 2002 until then, when
developing film (usually Kodak, usually ISO 200), I asked for scans on a
CD. (I was using a Ricoh KR10 Super.) Depending on various things,
including where I got the film developed and scanned, these are about
500--1500 kB. JPEG files produced by the K10D (set to produce the best
and highest-resolution JPEG files) are between 2 and 4 MB.

Does it appear possible that re-scanning the film in higher resolution
would produce better results? (Of course one can scan it in arbitrarily
high resolution and produce arbitrarily large JPEG files. The point is,
what resolution is meaningful and what file size should that produce.)

4000 dpi is a good practical limit for basic scanning (dry air). So a
Minolta 5400, Nikon 4000, etc. are fine scanners for the job.

A 4000 dpi scan results in:
4000 x 36/25.4 X 4000 x 24/25.4 = 21.4 Mpix.

Bit depths are 12 or 14 bits/colour, but typically encoded as full
words, so the file size (uncompressed TIF) will run up to:

21,400,000 x 6 = 128 MB - though my TIF's usually run about 85 MB. In
JPG that will come down quite a bit. (less than 20 MB).

"Wet" scanning up to about 8000 dpi or so will give cleaner, better
contrast ... but it's expensive if you don't have the equipment.

You can get a wet scanning kit for the Nikon 8000/9000 scanners that
provides converted trays that use an oil (?) as the wet media. That
improved contrast but doesn't increase the resolution of course.

Digital cameras have little dyncamic noise and 0 dimensional noise, so
images are always much cleaner on digital cameras for a given lens, ISO,
shutter speed and lighting conditions.

When I compare the JPEG files on a computer screen, those from the K10D
definitely look better. They are completely sharp on a 17-inch screen
(scaled to about 1/3); in full size, one notices that they are not
infinitely sharp, but they still look OK. The ones from film on
screen (scaled to about 2/3) look OK, but one sees that they are not
infinitely sharp even when scaled down to fit the screen.

When comparing 4x6-inch (10x15-cm) glossy prints, those from the K10D
look better, but only slightly so. This is why I suspect that
rescanning the film would improve the quality.

What resolution do people recommend for ISO200 film? What would be the
resulting JPEG size?

I likes various Kodak chromes (elite chrome, kodachromes...) and Velvia
from Fuji.

For negatives, the cleanest scans were from Fuji Portra 160 (exposed as
100). Colour was just a tad above neutral.


Of course, I could ask whether it is worth it to rescan the film from
2002 to 2008. However, I definitely want to scan my film from the 20
years before 2002. (I was using a similar Ricoh model, KR5 IIRC, for
most of this time. It was stolen and I replaced it with the used Ricoh
mentioned above. They were very similar except that the second one had
an automatic setting where one could set the stop and it would set the
time; also, the light meter looked a bit different.) If I do so, I want
to get it right the first time. Also, this is much more than
2002--2008, so it wouldn't be that much more effort to scan rescan the
stuff I already have.

For a couple of thousand pictures, what would be a reasonable price?

You could buy a used scanner (Nikon 4000/5000, Minolta 5400...) and then
scan the ones worth scanning. Scanning services will not give you the
max resolution available (generally).