Re: Gum and contrast (was: UV printing systems)

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From: Judy Seigel (jseigel@panix.com)
Date: 10/18/01-10:03:14 PM Z


On Thu, 18 Oct 2001, Sandy King wrote:
>
> Actually the daylight tubes worked very well with gum for Phil Davis,

Actually they didn't -- but he didn't know any better, making statements
about "the nature" of gum printing based on those cockamamie bulbs, and
boasting how much money he saved with them, rather than buying BL.

I refer to his (1995?) article in Photo Techniques. So I bought 6 of the
bulbs to try, and found that they would make a gum print of sorts, feebly,
but quite off on contrast, length of exposure (about 4 times as long), &
so forth. I wrote a very gentle letter to editor Mike Johnston, generally
praising the article, but pointing out some of the mistakes. (One I
remember in particular was his statement that if the highlights hadn't
cleared in an hour, consider the print spoiled... there were others,
equally bizarre. He didn't smooth or burnish emulsion, simply spread it
on. And so forth. Is it any wonder his "rules" were meaningless?)

I stil have that exchange on file... another reason (even if not forced
by a higher power) I had to start Post-Factory -- to get straight plain
FACT in print. Johnston himself seemed to understand that I was right,
despite his name calling and what a colleague called his (oh what is that
dog, not a pit bull, a meaner one) let's say attack dog style... as
whoever was not one of his demigods might suffer...

Besides, which, he said, "I don't do that to my writers." I suggested,
mildly as possible, that he owed it to his readers -- that even the NY
Times prints amendations or amplifying info. But he wasn't having any. So
in one breath he accused me of -- oh I don't know, some baseball metaphor,
pitching from the dugout?, and in the next urged me to write a gum article
for him. Sometime later he even recommended me as "expert" on gum to well
known fella looking for same.

And so we see that (besides being right about the errors), I was right
about the readers (and I do so love those times, much rarer than they
would be in a more perfect world) when I am indeed RIGHT !!! -- a whole
generation, perhaps what remains of future alt on earth, is misled
(pronounced miss-led) by Johnston's, um, how can I say this politely? --
misguided principles of editing.

> Looking at the literature in Kosar indicates that a vast amount of
> testing of colloids was done in the past and there are apparently far
> more similarities than differences in the way different ones react to
> light and the dichromates and chromates.

Saying "colloids" is like saying "women," or "Americans." Each one is
different, even sisters, even identical twins. If colloids were the same,
we'd only need one. And even if "There are apparently far more
similarities than differences" is true, god (or maybe it was the devil?)
is in the details.

> And no, I have not done any testing with gum. However, the literature
> suggests that all of the colloids have similar spectral sensitivity
> requirements (and thus should react in a similar way to different
> light sources), which is really the only point I wanted to make in
> comparing gum and carbon.

I do not believe there is enough ink in the world to correct all the error
(especially the "should's" -- in which Kosar is especially rich) in "the
literature"...assuming the part I'm familiar with is average. And to make
this more general, I've noticed that in the past year, the New York Times
science page (my window on the world) has reported some 6 or more
instances in which established principles of science & medicine
(heartbeats per minute in exercise, healing of nerves, speed of light,
etc. etc.) were proven wrong.

Which as far as I'm concerned is just dandy -- gives us room.

But anyway & meanwhile, couldn't we take the fact that those bulbs worked
for carbon and NOT for gum as PROOF of the fallacy about "colloids" as
being essentially the same?

> Ultraviolet light by convention is often divided into three areas,
> UVA, in the 320-400 nm, UVB, 280-320 nm, and UVC, 200-280 nm.

Thanks.... The "literature" I read (leaflet with a small low-spectrum UV
light I'd hope would spot expose, but didn't) called those areas something
like high, middle and low UV.

best,

Judy


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