DITTO with correction

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Grafist@aol.com
Date: 12/19/01-10:47:19 AM Z


In a message dated 18/12/01 00:45:30 GMT Standard Time, holtsg@duke.usask.ca
writes:

> This just a little off topic, but not too far...

                 Compared with much posting of late this is right on
topic..... not that I am complaining. I do, nowadays in fact, delete most
postings, before reading.
>
> Was reading an old reference on photochemistry and came across a very
> small section on latentsification (SP?!). This is the practice of
> treating film after exposure, but prior to development to increase a film
> sensitivity.

      So,actually, it is an initial part of the development of the latent
image. Right?
>
> Most of the techniques are bizarre and impractical but a couple looked
> practical. One was soaking the film in a solution of oxalic acid before
> development. I tried this and it did alter the way the film developed it
> did not appear to increase sensitivity - the film wasn't denser.

           I have been using DIAFINE TWO BATH developer for many years. This
system seperates into two solutions the usual constituents of a one bath
developer. It gives maximum "speed" and an increase in "sensitivity" ( the
two concepts are linked) to a film emulsion. This is not "intensification" of
the final image. Intensifiers work on the developed and fixed out image. This
development of the latent image takes place before fixing and may be
intensified, even further, after the film has been completely processed.
                  I am sure there has been much experimentation in this field
of increased emulsion sensitivity. BTW Diafine has an EXTREMELY long working
or shelf life. I made some up in nineteen eighty nine and it is **STILL**
giving me full density negs.
        A 400 ASA film (e.g.TRI X) is rated at 1600 ASA in DIAFINE.

Thanks for bringing up an "off topic" off topic topic. May we have many more.
A HAPPY SEASONAL GREETING TO ALL MEMBERS OF THE LIST FROM
                    John Grocott - PHOTOGRAPHIST
                                       (London, England)
>
> Does anyone have any experience or even success, with anything like this?
>
> Gord

               P. S . Further details if anyone's interested. HAPPY NEW YEAR
                             JOHN


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