From: Rod Fleming (rodfleming@sol.co.uk)
Date: 04/12/00-02:44:36 PM Z
Hi
My name's Rod Fleming. I've been listening in here a while and learning a
lot about alternative processes; however, this discussion is about
non-alternative processes, and I've been in there a while.
Gregory Parkinson is definitely reading the wrong books. To start with even
among the most optimistic home/office scanner manufacturers, 300dpi, not
200, is regarded as "photo quality". However if you actually examine a
really high quality offset print on glossy art under the loupe and then
examine a gelatin print, you'll realise that even 300 dpi is nowhere near
real "photo quality", even as far as 35mm is concerned, and not even in the
ballpark when it comes to larger formats!
The print emulsion is capable of holding far higher resolution than an
enlarged film image can throw at it, and indeed the suggestion that a print
emulsion is only capable of a maximum resolution of 200 dpi (or for that
matter 300 dpi) is just funny. The emulsion on a sheet of paper is not
radically dissimilar to that on a film, and we know that slow film will
conservatively hold at least 80 lines per millimetre, which is over 2000
dpi. Fuji Crystal Archive has a nominal speed of 400 iso, but even if that
could only separate 40 lines/millimetre, that's still over 1000 dpi _on the
print!_ (I know the two measures should not really be compared like that, in
this case it's justified.)
Given that we are discussing professional quality lenses here, the fact is
that even 35mm is well capable of producing stunning results at magazine
size on glossy art- if you don't believe me, go and get a copy of "National
Geographic"- but only when the scans have been done properly, and this means
a Linotype/Hell drum scanner or equivalent, operated, may I add, by a
talented person; scanning on these machines is not the same as shoving a
print in your desktop flatbed.........
Though the transparency was once the undisputed king, and is still the
picture editor's favourite because it's just so easy to sort them out on the
lightbox, these days a good scanner operator can get excellent Dmax out of a
print, so the rule, for c-type anyway, has to be, make the biggest best
print you can (so long as it will go on the drum- 10x12 is a good size) and
scan that on serious drum scanner.
BUT, if you're producing for newsprint, which will toil to hold better than
120 dpi, with limited Dmax, the desktop scanner, particularly the desktop
film scanner, is an excellent tool. If all you're doing is outputting to a
home/office inkjet, which has Dmax which is pathetic compared to a gelatin
print, it's more than adequate. And frankly, if you're scanning for
website/online use, it's too good. Let's just not pretend that it is more
than it is- really high quality repro needs better, and home/office digital
has some way to go.
Cheers
Rod
----- Original Message -----
From: Mats Broberg <mbroberg@swipnet.se>
To: Alternative Photographic Processes <alt-photo-process-l@skyway.usask.ca>
Sent: 12 April 2000 17:56
Subject: Re: colour neg scan
> Gregory Parkinson wrote:
>
> > I've been reading a lot on scanning and one number I've come across
> > is that color prints don't give you any better than 200dpi - so scanning
> > at a higher resolution is pointless. I supposed if your prints were
> > large enough you'd get additional dots in the final scan.
>
> The resolution of a (photographic) color print is the same as the number
> of gelatin grains per inch in the emulsion, which exceeds 200 dpi by
> many many times. It's true that you don't need them if you don't plan on
> blowing up a 6 x 6 neg to wall size, but IF you plan to output a
> considerably larger (offset or the equivalent) print than the original,
> it is usually better to do most of the blowing up photographically than
> on the scanner.
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