----- Original Message -----
From: "Mick Maguire" <
Subject: Push 101
> OK, I don't count myself new to photography by any means (been
using a
> camera for 20 years or more), but I have only recently been
looking at it
> much more seriously. Can somebody give me a "Push" 101? All I
know is it is
> to do with exposing and/or developing film at a different
speed to what it
> is sold as. Or at least that's what I think. How and why would
I do this
> exactly, and how would I relay this info to the lab?
Sure.
Push 101: It doesn't work.
Now that we have that out of the way. let me explain why.
What we are trying to do is to get something for nothing, more
or less.
Once an exposure falls under the threshold level for causing a
latent image, nothing will develop on the film.
An average exposure scene is around 6 stops (go and check it
yourself, don't just ask me to accept you have an exception that
disproves this).
The iso of the film is based on the amount of exposure required
to capture a scene.
If you expose the film for less than is required, nothing will
get the lost detail back. It isn't there to develop.
If you exceed the time required for proper development, you
increase the contrast of the film.
You do not get back detail that fell below the threshold
exposure.
What is far better than "push" processing is a scientific
approach where you decide what is the darkest part of the scene
that you cannot live without detail in, and expose accordingly,
based on what you have determined to be the iso of the film in
your conditions (not necessarily the speed printed on the box),
then adjust the development to give a normal tonal range.
Pushing C-41 film doesn't work under any circumstances (yes, I
can offer proof).
Apparently, people successfully push E-6 film. Not me.
People think they can successfully push B&W. They are fooling
themselves.
All they can do is accept less than nominal results, and be
happy that they at least got a picture.
If you are going to insist on trying to push film, choose a low
contrast one. T-Max P3200 is a good choice.
Tri-X has an extremely long toe, which makes it a good candidate
for abuse.
I used to shoot Tri-X at ISO 1250 and process it in Diafine. I
thought the results were wonderful.
You might too.
William Robb
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