Archived posting to the Leica Users Group, 1998/09/04

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Subject: Re: [Leica] Erwin and TMZ
From: Eric Welch <>
Date: Fri, 04 Sep 1998 19:46:30 -0500

At 07:25 AM 9/4/98 -0700, you wrote:

>What do you think of processing at whatever the current room temperature
>is, and adjusting the development time based on the deviation from 68
>degrees?  I read somewhere that a good adjustment factor is 10% for each
>4 degrees.  I haven't experimented with this, but if it works it'll make
>processing much more enjoyable.

I don't because TMax films are optimized to be processed at 75 degrees.
It's a whole lot easier to remember processing times too when you use three
different films and push and pull one of them at four different speeds and
another six different speeds.*

According to John Sexton, who was one of their testers (I was too, but they
didn't listen nearly as closely to me as him! <G>)  the mid-tones are
optimum at 75 degrees. I found him to be correct. Using Leica lenses, we
should be optimizing our development as much as possible. No?

As a photojournalist often processing my stuff on deadline (that is, walk
into the darkroom at 8:50 and have the pictures in the system by 9:30) I
used 85 degrees for speed. And 75 degrees when not on deadline.

(* Tmax 100 at 100 - TMax 400 at 200, 400, 800, 1600 and P3200 at 400, 800,
1600, 3200, 6400 and 12,800. Now it's Ektapress 100, Fujicolor 400 and 800
- - the latter pushed up to 3200. I do miss black and white.) 
- -- 

Eric Welch
St. Joseph, MO

Prepositions are not words to end sentences with.