more dag questions

From: Agustin ^lt;[email protected]>
Date: 01/10/04-10:25:09 AM Z
Message-id: <001301c3d796$587ed840$afe3fea9@h13225.tdmy.com>

Stuart. I donīt have experience with daguerreotypes. I took some personal classes with a really close friend that used to make mercury developed dags. We finished getting 3 correctly exposed and polished plates, after a dozen of attempts. The problem was that we were using new plates (pure silver) and they werenīt 100% pure.
I donīt know actually the differences in the image between Mercury development and the Bequerel process, but with mercury, developing times are arround 1 to 3 minutes, when with Bequerel, you have to expose the plate to Uv light for many hours (Christopher will shurelly give you better advices with Bequerel).
The differences between Iodine and Bromine reside in the exposure time. With Iodine, the times we needed to get a well exposed plate, were arround 5/10 minutes (f:5,6) in sunlight. Thatīs why it is really hard to get a good protrait with iodine sensibilization. The Bromine, adds (as you know) 2 more steps in the sensibilization, and that means, less chances to get the plate correctly. But with Bromine, exposure times are really shortened. (I donīt know how much exactly), and you are able to take good portraits. I think Spagnoli portraits are made with the bromine process.
I still have to build the dev. and sensibilization boxes to start making the dags here at my place.

Good luck.

Agustin.
Received on Sat Jan 10 10:27:00 2004

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