From: martinm (martinm@SoftHome.net)
Date: 07/25/03-11:07:45 PM Z
----- Original Message -----
From: "Ryuji Suzuki" <rs@silvergrain.org>
To: <alt-photo-process-l@sask.usask.ca>; <martinm@SoftHome.net>
Sent: Friday, July 25, 2003 8:41 AM
Subject: Re: Bromo-iodide Silver Gelatin Emulsion as an Alternative process
> I can't look it up now, but I remember Baker's book described a that
> dye (along with Orthochrome T) with suggested doses in terms of a per
> cent fraction of AgBr (was it something like 0.05%?). (definitely not
> meant to be a recipe.)
The formula I found is based on Baker:
A
gelatin............................20 g
water.........................390 ml
Gelatin is dissolved at 35°C and then filtered. Take 80 ml of solution A and
add solution B to it:
B
silver nitrate.....................4 g
water...........................10 ml
To the balance of solution A add and dissolve 3.2 g potassium bromide. When
KBr has been completely dissolved, the solution is slowly opoured into the
gelatin silver-nitrate solution. After precipitation add the following dye
solutions:
Pinacyanol............................(1:1000 alcoholic solution) 4 ml
Orthochrom T......................(1:1000 alcoholic solution) 4 ml
Acridine orange......................(1:500 alcoholic solution) 4 ml
It appears that this dye combination goes back to Lehmann who patented a
Lippmann emulsion (~ 1905).
Martin
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