Re: [APML] General question

[Roland Roberts <roland@astrofoto.org>]

>>>>> "David" == David Keeley <drmellow@davekeeley.com> writes:

    David> I had a question and was wondering if someone could assist
    David> me?  I've read where people say they "push" their film one
    David> step.. What is meant by that? Is it something done at the
    David> developing lab i.e.  developing 200 ASA film at 400 ASA?
 
Yes, the lab does it.  "Pushing" means developing the film a bit longer
(or at a higher temperature); "pulling" is developing it a bit shorter
(or at a lower temperature).  "Push +1" means developing it to give the
equivalent of a one-stop increase in exposure.

Any pro lab should be able to do this, but the typical drug-store can't
(actually, I wouldn't be at all surprise to learn that the equipment can
but the operators don't know how).  A common reason to push is also to
move the slide shadow regions out of the scanner no-man's-land.

For some B&W films, the technical documentation will tell you how to
develop and how to push or pull as well (e.g., the Tech Pan docs do, as
do the T-Max docs).

regards,

roland
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Roland B. Roberts, PhD                             RL Enterprises
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