Brad,
Plates fumed with iodine and bromine and mercury developed are many
times faster than
Becquerel plates. Typical exposures for Hg plates are 30 to 90 seconds.
Becquerel plates require exposures of 20 minutes and up. Hg plates
development is a matter of a few minutes. Becquerel
plate require an hour or more of development.
Bob Schramm
Check out my web page at:
>From: Bradley Lewis <bal101@psu.edu>
>Reply-To: alt-photo-process-l@usask.ca
>To: alt-photo-process-l@usask.ca
>Subject: Dag Questions
>Date: Thu, 10 Aug 2006 01:28:56 -0400
>
>I have a couple questions for the Daguerreotypists out there. I really
>want to get into making my own Dags, but don't think I'll be able to attend
>any workshops on the subject. Fortunately, I am a chemist, so a lot of the
>procedures involved are not too foreign to me, hopefully.
>
>First, I was wondering about the thickness of the silver plating on the
>copper. I would like to plate the copper myself. I have read somewhere a
>figure of 0.35 mil or about 10 micrometers. Any idea if this is correct,
>or what range of thicknesses work? Does anyone have a feeling for how the
>thickness of the silver layer affects the image?
>
>Second, I was wondering about the development methods. How do mercury
>developed images differ from Becquerel developed images? I can obtain and
>handle mercury fairly easily, but if there's no real advantage, I think I
>would prefer using the Becquerel method.
>
>I hope I'm not inundating you with questions. Any advise offered would be
>deeply appreciated!
>
>Thanks for your time and assistance in this.
>
>Cheers,
>
>Brad
Received on 08/10/06-10:38:48 AM Z
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