what's on second (was: who's on first)

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Sat, 19 Apr 1997 17:32:20 -0500
>From: P3D ron labbe  <studio3d@xxxxxxxx>
>Subject: who's on first

>John Roberts wrote:
>>I don't accept the premise. Developed slides are second generation.

>WHAT??? So UNDEVELOPED slides are FIRST generation? 

I didn't say that.

>Ah, i uh, don't accept the premise... 

Do you understand the reason for each step in the processing of slide film?
I don't know what the specific steps are for processing Kodachrome, but as
of a few years ago, processing of Ektachrome took two "major" steps, and
unless there's been a real revolution in photographic processing, I expect
that's still the case. The initial exposure of the film and the first part
of the processing actually produces a "negative" on the film. The negative
image must then be put through another color reversal (used to "expose" a
second set of media), the double-reversed image developed, and the "negative"
removed or made transparent. (There are other details such as washing that I
don't recall in detail at the moment - it's been several years since I made
a study of it - I broke my good thermometer, and the process I was interested
in required a temperature regulation to within 1/4(?) degree F.)

I believe some processes for the second reversal have actually required that
the slide film be exposed to a (non-imaging) light source in the darkroom 
as an intermediate step, but that later processes make it possible to perform 
the second exposure chemically.

I think the original Polaroid film had a separate negative that you
would peel off after a certain amount of time - I think that kind may
still be available (we have an ancient oscilloscope camera that uses it).
But the newer kind retains the negative inside the picture indefinitely -
I think they make it transparent.

It's true that the second generation in the processing of a slide doesn't
involve passing the image through a lens system, but that doesn't mean that
you can't have effects such as spreading of the image elements and increase
in the contrast. Anyway, the premise that I did not accept was that slides
are purely first generation, and prints are always second generation. If
someone were to argue that the second stage in the processing of a slide
doesn't "count" because it doesn't go through a lens, then it could be pointed
out that the exposure of a contact print doesn't go through a lens either,
so by that definition a contact print would be "first generation". But I
think both arguments (in the previous sentence) are pretty weak - I consider
both slides and contact prints to be second generation.

>...in fact, I might go so far as to opine that it's ridiculous.

Well, I agree, but lots of Realist users seem to like 'em anyway.
:-)   :-)   :-)

John R


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