Re: Dry Plate Speed & Shelflife

-----Original Message-----
From: Ryuji Suzuki <rs@AgX.st>
Sent: Mar 6, 2005 10:52 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Dry Plate Speed & Shelflife

From: MARTINM <martinm@SoftHome.net>
Subject: Re: Dry Plate Speed & Shelflife
Date: Sun, 06 Mar 2005 11:54:17 +0100

> Ryuji, frankly, I am absolutely not keen on competing with your
> semi-professional (non reduction sensitized) silver halide
> emulsion. I am only interested in ultra-fine emulsions. [...]

As far as I know, this thread was about the speed and other characters
of color blind dry plate emulsions from early years of silver-gelatin
process, of course for pictorial photography applications. It
wasn't about holography or about how to make emulsions. In this
context you brought up one method to make holography plate and
adovocated its application for pictorial photography. Speed of ASA 50
was mentioned. I simply maintained that these are overselling stuff.

> I assumed, given the long tradition of this kind of SH emulsion
> making ("bathing method") it fit well with the philosophy of
> alt.photography.

That should have read "a long tradition of being abandoned as a way to
prepare pictorial quality emulsions."

> I guessed it would be silly to neglect more than one and a half
> century of experience made by people around the world (from Talbot,
> Poitevin, Liesegang till now) with different kinds of bathing
> methods.

I am not neglecting the history. I am deliberately preferring
post-1880 way of emulsion making.

--
Ryuji Suzuki
    Ryuji, can you give a very rough time line for the differrent methods of emulsion making, i.e., ripening vs other methods like reduction sensitizing etc. There must have been very rapid changes between say 1880 and say 1900 or even 1890. 
--
Richard Knoppow
dickburk@ix.netcom.com
Los Angeles, CA, USA