[pure-silver] Re: William Mortensen's Glycin Developer

----- 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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