Re: [Leica] B&W film speed

["Joe Stephenson" <joeleica@flash.net>]

Dear Gib,
Except for T-MAX 100, I expose all B&W ASA 100 films at 100 and never
compensate with development. I may fudge the meter reading a bit if I think
it's needed. But I feel development compensation is most useful with sheet
film where it's easy to process each sheet, or groups of sheets as desired.
I really don't know anyone who pushes or pulls when developing film, except
in unusual situations.
Sincerely,
Joe Stephenson

- -----Original Message-----
From: Gib Robinson <robinson@sfsu.edu>
To: Leica List <leica-users@mejac.palo-alto.ca.us>
Date: Sunday, February 21, 1999 8:35 AM
Subject: [Leica] B&W film speed


>To LUGers with darkrooms:
>
>Recently Nathan Wajsman listed the ISO/EI speeds he uses to expose various
>B&W emulsions (Delta 100 at EI=80, etc.). The impression I get from his
post
>and from other posts on the topic of film speed is that he and others of
you
>with darkrooms generally shoot a given B&W film at the SAME ISO/EI speed
>irrespective of lighting conditions. Is that true? If so, WHY? (As my
>daughter so frequently says these days).
>
>Those of us using commercial labs may not have the option of varying
>development times, but I assume those of you with darkrooms DO change BOTH
>exposure times and development times to control contrast. For example, for
>PAN films in high contrasting situations (rodeo riders in bright sun at
high
>noon), I would be inclined to over expose (effectively increase the film's
>ISO) to preserve shadow detail and under develop in the darkroom to control
>high lights. That way, I would be likely to get a smoother, more printable
>negative to work with.
>
>So, if I have access to a darkroom and I'm in control of the films
>development process, I don't just assign one ISO/EI number to an emulsion.
I
>may have a base number I start from under "normal" lighting conditions, but
>I vary that number according to the specific lighting conditions I face
when
>I shoot a roll and the specific sort of results I want with respect to
>contrast range on the negative. Am I making sense here? Is that how you
>folks with darkrooms work or do you stick with one film speed for each
>emulsion?
>
>--Gib
>
>
>