Archived posting to the Leica Users Group, 2002/01/15

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Subject: Re: [Leica] Delta 3200 & Neopan 1600 pushed...
From: "Don Dory" <dorysrus@mindspring.com>
Date: Tue, 15 Jan 2002 22:15:15 -0500
References: <B86A476A.862E%Mail@SlideOne.com>

John, real pushing means that the low areas change in response to changes in
exposure.  Most films and developers respond to
underexposure/overdevelopment by increasing density in the midtones to
highlights with the shadow detail going away directly proportional to the
amount underexposed.  Meaning zone III goes to zone I in a two stop push.

Full film speed means that when exposed at the rated speed the gray scale
falls as metered.  If I recall correctly that also means that an area
metered and exposed to produce zone I will produce a density on the neg. at
0.1 over film base plus fog.

In answer to your final question, it depends.  Increased development will
move the areas of the negative that had more photons in a non linear
fashion.  Or, to be plain, the contrast goes up.  So, on your thin negative,
the thinnest parts will probably not change appreciably in density while the
highlights will blow out.

The idea behind the super speed films is that for the first one or two stops
there was a linear relationship between increased development and movement
at the "speed point".  For a lot of people, that doesn't happen which is why
there is so much comment about shooting at 1200-1600.

Don Dory
dorysrus@mindspring.com

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In reply to: Message from John Straus <Mail@SlideOne.com> (Re: [Leica] Delta 3200 & Neopan 1600 pushed...)