From: Linas Kudzma (lkudzma@earthlink.net)
Date: 01/01/02-03:40:53 PM Z
Sandy,
The metol formulation I use (pieced together from info on
unblinkingeye.com) contains considerably less metol (not 10x the phenidone
amount) than what you state below. The formulas on the unblinkingeye site
give 0.2 g phenidone or 0.25 g metol per 100 mL of the respective solution
A.
Is there a typo somewhere or have you increased the amount of metol you
recommend. I don't have your original Postfactory article. My solution A
with 0.25 g metol per 100 mL of solution A works fine. I'm assuming that
the catechol continually regenerates oxidized metol in the usual
"superadditive" manner.
Linas
> [Original Message]
> From: Sandy King <sanking@clemson.edu>
> To: <alt-photo-process-l@sask.usask.ca>
> Date: 12/31/2001 10:05:44 AM
> Subject: Re: Stain Redux - Pyrocat HD and Tri-X: was Double Dipping
>
> Carl,
>
> There was an increase in effective film speed with the phenidone
> version of Pyrocat when I compared it to metol in laboratory tests.
> Although the increase is small - less than 1/4 stop - and might not
> be observable in field photography, I decided that the gain in speed
> was worth the trade-off in loss of stability of Solution A of the
> stock formula.
>
> For those who prefer to use metol, substitute it at about 10X the
> amount of phenidone specified in the formula. Also, it is probably
> best to add it to the solution before the bisulfite.
>
>
> Sandy
>
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