the edge effects (was BMF whatever)


Judy Seigel (jseigel@panix.com)
Fri, 29 Jan 1999 02:31:04 -0500 (EST)


There was an article in the Times the other day explaining that e-mail is
now considered a bona fide addiction, but I couldn't get offline long
enough to read it. It may be, however, that comparatively speaking, I am
still in relatively good shape. In the time since I checked this AM, an
entire concept has been proposed, considered, and practically published.
So I start at the beginning ...

On Thu, 28 Jan 1999 FotoDave@aol.com wrote:
 
> ...I have never thought that experienced photographers like Carl, Sandy,
> Hutching, and hundreds or thousands of pyro users (there is a pyro maniac
> group!) have problematic vision that they see things that don't exist at all.
> My question last year (or 2 years ago) was not whether pyro gives different
> result but whether this result can be achieved only by pyro or can be achieved
> in a "normal" but diluted, compensating developer. Even if it can be achieved
> with some ordinary MQ developer, I still won't go against pyro. Why would I?
>
> But that was last year, and that was before I ran my own tests on lith film.
> Now I am very sure that the edge adjacency effect CAN be achieved with
> ordinary developers. In fact, it can be achieved TOO EASILY with diluted
> Dektol. The effect is too much to be really useful. Trying to reduce its
> effect in Dektol gives the familiar contradicting requirements: we need less
> dilution to decrease the excessive edge effect, but we need more dilution to
> decrease the excessive contrast. (but I happen to have a gum print with that
> effect from Dektol which is not too excessive. The print is lovely. The petals
> of the flower looks like it is jumping out of the paper!)
>
> With all the curves already done (with D76, LC-1 as published in the journal
> and many other curves not published in that article), I can easily come up
> with a dilution / time that gives that adjacency effect. If there is some
> interest, please let me know, and I will put it as a test to be run. I can
> either publish the result on my web page in on the journal if Judy is also
> interested.

Dave, of course I'm interested. That's a GREAT project... and one of those
experiments where you win either way: no matter what the "answer", the
information cannot help but be fascinating. The point I wonder about,
though, is how you're going to determine if results are comparable. Only
way I can think of is to make the print and measure reflective density,
because otherwise I don't know how you'd measure the effect of the
stain....or, rather, compare the effects of the different stains.

In any event, there's an article scheduled on pyro by another celebrity
on this list... the two could bounce off each other.

Meanwhile, speaking of edge effects, and for what it's worth -- about 3
years ago, when I first began testing lith film, Kodak sent me samples of
a couple of its new "liths" -- one with 2000 in the name, as I recall, and
another. One was the deluxe, the other economy, probably designed to
compete with the Arista, both for imagesetters. There was a dedicated
developer, which I used, as well as the usual dektol. To my astonishment,
there were EXTREME edge effects when developed for continuous tone in
dilute developer -- so extreme it looked like Sabatier. It was a great
temptation to play with that, but there are just so many games a person
can play , and I didn't... The tests proved decisively that the Arista is
better for continuous tone, and I let the matter drop.... Since all I
tried were step wedges, and the "Mackie lines" were around the numbers, I
realize it may not have worked with a contone image -- but it was pretty
spooky.

Judy



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