RE: Dry Plate Speed & Shelflife

The old text by M. Carey Lea discusses the 19th century state-of-the-art
thinking for making dry plates toward the end of the book. It is a very
thorough book that is available from the U Mich site:

http://www.hti.umich.edu/cgi/b/bib/bibperm?q1=aEL5141

Clay

> -----Original Message-----
> From: Robert Newcomb [mailto:newcombr@uga.edu]
> Sent: Tuesday, March 01, 2005 10:53 AM
> To: alt-photo-process-l@skyway.usask.ca
> Subject: Dry Plate Speed & Shelflife
>
> I've been interested in making my own glass dry-plates to shoot in
> camera - I like some of the "errors" introduced from hand poured
> emulsions.
> A couple of questions for all you knowledgeable people out there.
> 1) I have read that the speed of early dry-plates was about 7 stops
> slower then the wet -plate process in use at the time. While I'm
> certainly not trying to shoot action sports shots, we're talking Very
> slow here. I have heard that the bottled silver emulsions have an in
> camera speed of about ISO 1/2- maybe 1.
> Is their a component (bromide?) or procedure that will make a hand
> poured dry plate at least as fast as wet plates?
> 2) I have also understood that early dry plates (hand poured) had a
> useful shelf-life of only a few days or a week after being made in
> which one must expose them. Is their a means of extending this
> shelf-life to a couple of weeks or at least something more the a few
> days? I'd hate to make them and then not be able to go out shooting
> the next day so the plate spoil.
> I understand that commercially prepared plates later overcame these
> factors but what is possible of the home brewer?
>
> Thank you,
> Robert Newcomb
Received on Tue Mar 1 11:00:11 2005