From: Sandy King (sanking@clemson.edu)
Date: 10/12/03-06:51:00 AM Z
Hi Scott,
Is this not the information you mention?
"I recommend a minimum of 50ml of the 1:1:100 dilution per 4X5" sheet
of film (20 square inches). This amounts to about 90ml for 5X7, 200ml
for 8X10, 385ml for 11X14, 300ml for 7X17, 600ml for 12X20, and
1200ml for 20X24. Remember, these are minimum amounts. With the
2:2:100 dilution the amounts can be reduced by about 20%."
All of my tests for speed are based on either the 1:1:100 dilution or
on 2:2:100 with rotary processing with sheet film. I don't test for
speed with roll film in tanks with stand development, though in
principle you should get full emulsion speed from the 2;2:400-500
dilution that I recommend.
One of the difficult things for a photographer to do is measure
effective film speed. This can not be done with standard equipment
because of variables in exposure meters, shutter speeds and evenin
the calibration of the lens aperture. My testing is done with a light
integrator that provides absolute accuracy of 1/100 of a second when
exposures are 1/10 of a second.
Sandy
>Hi Sandy,
>
>Great article!
>
>With one exception, in the rotary processing section, I saw no
>mention of a minimum quantity for parts A & B. In the past I used a
>3+3+1200 dilution with stand processing for 90 minutes with Arista
>125 film (80 sqin) and had to give en EI rating of 50 to get negs
>that printed well on a grade 3 to 3 1/2 SG paper. I just shot a film
>speed test using a 4+4+1000 dilution with 60 minute stand
>development for the same film (same batch #) and got an EI of 80.
>From this, I would assume that I was exhausting the developer with
>the original developer. Any thoughts?
>
>Regards,
>
>Scott Wainer
><mailto:smwbmp@starpower.net>smwbmp@starpower.net
>
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