[pure-silver] Re: William Mortensen's Glycin Developer
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 16 Dec 2004 12:38:56 -0800
----- Original Message -----
From: "Koch, Gerald" <gkoch02@xxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Thursday, December 16, 2004 7:58 AM
Subject: [pure-silver] Re: William Mortensen's Glycin
Developer
> Mortensen evidently used more than one developer for his
> "gamma-infinity"
> method. The following formula is also cited for this
> method.
>
> Water .................................. 750 ml
> Sodium sulfite (anhy) .................. 90.0 g
> Paraphenylenediamine ................... 12.0 g
> Metol .................................. 7.0 g
> Benzoic acid ........................... 6.0 g
> Water to make .......................... 1.0 l
>
> Both formulas require long development times. For the
> above formula this time
> is required to produce sufficient contrast and for the
> other formula to produce
> sufficient density.
>
> Jerry
>
Compare this to DuPont Sease No.1
Water 750.0 ml
Sodium Sulfite, dessicated 90.0 grams
P-phenylenediamine 10.0 grams
Water to make 1.0 liter
This required anywhere from 12 minutes (microfilm) to 50
minutes (medium speed motion picture negative) for the
various Dupont films of the time (c.1944). Speed loss varies
with the film but is on the order of 4 stops.
I wonder what the Benzoic acid in Mortensen's formula
does. I have some memory it is a hardener but could be
remembering wrong. In any case, it probably lowers the
activity somewhat.
I suspect either developer would produce excessive
dichroic fog on modern films. IMO these formulas are more of
academic interest than practical.
V.B.Sease of Dupont published a series of
p-Phenylenediamine formulas with different amounts of Glycin
in them. No.1, above, has no Glycin. Increasing the Glycin
reduces the speed loss, increases the rate of development,
and increases grain.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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