Archived posting to the Leica Users Group, 2006/02/05

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Subject: [Leica] Recommendations re: Kodak 3200 ASA
From: shino at panix.com (Rei Shinozuka)
Date: Sun Feb 5 16:28:44 2006
References: <43E44556.2060001@gmail.com> <B9C6C3CE-2E7E-4685-B6EE-6A1FE1205BC4@pandora.be> <43E55E4F.70301@gmail.com> <15271210.1139106748845.JavaMail.s_gregory1@mac.com> <22c93b290602051052w128f1026n591b9505943269b8@mail.gmail.com> <6.2.5.6.2.20060205212353.0313a3e0@screengang.com> <22c93b290602051546r17c62861hcef8b9c78405f709@mail.gmail.com>

one can define an objective film speed as well as development time
as those such that a zone I exposure (4 stops underexposed) is on the
negative about 0.10 above the film base plus fog on a densitometer, 
and zone VIII (3 stops overexposed) is about 1.25 above film base plus fog.
adams and picker talk about this in their books, adams has graphs of
various films in _the negative_.

you can take a 400 film, shoot it at 1600 and develop the heck out of it, 
and your zone V may fall with a density of around 0.75,  but your zone I
will be inseperable from fog and zone VIII might be blocked.  it's not
to say this is ill-advised, but the film's "true" speed will not be 1600,
it would be a 400 film underexposed and developed to the point where the 
midtones fall about where a "true" 1600 film's midtones would fall.

-rei



On Feb05 17:46, Matt Powell wrote:
> On 2/5/06, Didier Ludwig <rangefinder@screengang.com> wrote:
> >
> > >... neither Delta 3200 nor TMax 3200 is a true 3200-speed film.
> > Matt
> > What do you ecaxtly mean with "not a true 3200-speed film"?  Just 
> > curious.
> > Didier
> 
> However ISO is measured (I believe it's shadow density at
> something-or-other blah blah blah, I don't do testing of that kind),
> neither of the 3200 films is a 'true' 3200 ISO (as Tri-X is a true 400
> in certain developers, etc.). TMZ or Delta3200 at 3200 is underexposed
> (and then push-processed).
> 
> This is all badly explained, I'm sure.
> 
> --
> MP
> wooderson@gmail.com
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information

-- 
Rei Shinozuka shino@panix.com
Ridgewood, New Jersey


Replies: Reply from tedgrant at shaw.ca (Ted Grant) ([Leica] Recommendations re: Kodak 3200 ASA)
In reply to: Message from evanowski at gmail.com (Edmund Evanowski) ([Leica] poorly framed & composed snaps?)
Message from philippe.orlent at pandora.be (Philippe Orlent) ([Leica] poorly framed & composed snaps?)
Message from evanowski at gmail.com (Edmund Evanowski) ([Leica] poorly framed & composed snaps?)
Message from s_gregory1 at mac.com (Scott Gregory) ([Leica] Recommendations re: Kodak 3200 ASA)
Message from wooderson at gmail.com (Matt Powell) ([Leica] Recommendations re: Kodak 3200 ASA)
Message from rangefinder at screengang.com (Didier Ludwig) ([Leica] Recommendations re: Kodak 3200 ASA)
Message from wooderson at gmail.com (Matt Powell) ([Leica] Recommendations re: Kodak 3200 ASA)