digital negatives -- an expert says


Judy Seigel (jseigel@panix.com)
Sun, 17 Jan 1999 21:49:57 -0500 (EST)


Dear Friends,

Things have been so peaceful lately I bet everyone's gone to sleep... and
I've been promising some report on digital negs for several days. I expect
to rouse some folks with the following advisory, about matters of which I
myself have only the most rudimentary knowledge. Maybe it's true, maybe
not. I pass it along to make of it what you will.

I spoke to my high-priced expert on the phone today, about various printer
questions. He was absolutely EMPHATIC about inkjet printers, saying they
are "junk," "garbage" and do not perform a good deal of the time. He says
he's lost money on installations in offices because he's had so many call
backs. "My clients are coming after me like villagers with torches after
Frankenstein," he said.

Now of course this is for professional situations, where high-end
performance is a must. It's entirely possible that for making of digital
negatives for personal use, the inkjet is just fine & dandy. I figured
though that's worth passing along, for what it's worth, as at least the
opinion of one person, whose advice I wish I'd had 2 years ago when I
hitched up with Ms Performah.

I myself am now thinking 11x17 inch laser printer, supposedly available in
closeout for less than $1000. I've been printing paper negatives on an
8-1/2 by 11 laser. The dots are very large -- which is fine for my graphic
effects in 3 color gum. But I'd like to get them smaller, or be able to,
which I couldn't without a memory upgrade. Since I find the 8-1/2 x 11
size very constricting, my thought is to put the $$ toward a larger
printer -- assuming I can find room for it. Maybe under a tablecloth to
eat on.

As for paper neg vs. acetate or film neg -- my present laser didn't print
well on the film I put through it. The dark dots got all mushy, making
contrast so weak, even at 20 nuarc units (my usual is 60 to 80 units for
color-separated gum), contrast didn't hold. I do have another film that
works better, but since it's 11 by 17 inches, and expensive, it seems a
pity to cut it up. So I'd say you have to try a given film with a given
printer to see how it works. Take a disk to the computer store and try the
printer on the film or whatever you're thinking of.( Even were I that kind
of person I wouldn't dare generalize across the board on this topic.)

Another thing I did this week was make negatives from some inkjet
interpositives a friend printed out for me years ago. The theory was that
since you couldn't get the density on inkjet film, you did the interpos
and contacted to lith to get a dense enough negative. (I think 3 years
later, which is about 6 computer generations, inkjet does get that
density, if not on film, certainly on paper, which you can wax.)

Actually making these negatives, once you have the times from an initial
test, hardly takes longer than waxing the paper, assuming you have access
to a darkroom. The tones were funny though, looked at through a loupe. I
don't think they do that any more, but they reminded me of the early
computer graphics -- was it Explor ?? -- in the '70s, when they first
began making pictures by printer: The midtones were a W, the darks were a
W printed on top of an M, the darkest darks were that with an X added in
the same space, etc. These acetates (or whatever they were) had a
different kind of pattern for each level of tone. They haven't printed
wonderfully yet, though I think I can do better with them when I figure
them out -- but they're so small it hardly seems worth the effort.

Finally, I read the printouts on acetate (or whatever the film is) on the
densitometer, and compared the readings to same file printed on paper
waxed and not waxed. As follows:

acetate:
-----------
clear: .12
medium gray .30
darkest.53

range: .41
clear to midtone: .18

waxed paper
-------------

clear: .32
medium gray: .65
darkest: 1.10

range: 78
to midtone: .33

paper not waxed
---------------

clear: .70
medium gray: 1.10
darkest: 1.44

range: .70
to midtone: .30

If you compare, you see that the paper picks up a bit of contrast in the
waxing. The waxed paper has nearly twice the range of this particular
acetate. But even on a *good* acetate, it probably might not be enough
for, say, platinum.

Also, I was reading the magenta separation, which is, or in this case was,
the flattest.

Cheers,

Judy



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