Re: Daguerreotypes again

From: Etienne Garbaux ^lt;[email protected]>
Date: 08/23/04-09:03:00 AM Z
Message-id: <p05210601bd4fad273790@[192.168.1.100]>

> It seems that there are those who HAVE learned the Dag process on
> their own, although I would never ever ever even think of beginning to
> deal with mercury without consulting with multiple professionals on
> this. Perhaps someone can confirm or deny this, but I have heard that
> the phrase (and character of) the "Mad Hatter" came about because
> there once was a day when men's top hapts were made to shine
> with.....guess what.....mercury......and they eventually went insane
> (for lack of any actual diagnoses).

According to the (US) National Institutes of Health, a mercuric nitrate
bath was used to shape the felt:

http://www.nih.gov/od/ors/ds/nomercury/

Of course, one needs to be aware of the hazards involved in handling
mercury and halide (iodine, bromine, chlorine) vapors, and be
comfortable about dealing with them. With a little thought, it is not
very difficult to protect oneself from them. Preventing release to the
rest of nature, which is much more of an issue now than when I learned
the Daguerrotype process, is substantially more difficult.

Once one is comfortable with this part of it ("Other than that, Mrs.
Lincoln, how was the play?"), learning (and even mastering) the process
is not, in my opinion, difficult. I assume that the alt-process worker
is experimentally inclined, and hopefully capable of being methodical.
As to "How polished does the plate need to be," one quickly learns that
whatever polishing one has done before the question is asked is just a
start. I wasn't fooling when I said Hubble-mirror finish. Yes, someone
can show you a good plate and give you tips on polishing methods, but
looking in metal polishing references (including Dag instructions) for
tips and looking at the plate with a powerful magnifier are all that
the experimentally-inclined worker needs. Similarly, metalworkers have
for several centuries been tempering steel after hardening by heating
until a surface film develops to colors such as "pale straw," "straw,"
"dark straw," "pale blue," "indigo," etc. Sure, someone can show you a
"proper straw" plate, but you don't really need this. With the first
plate, the new worker shoots for "straw" as best as (s)he can, and sees
what happens. The next two times, (s)he shoots for "pale straw" and
"dark straw," and sees which improves things. By the 5th or 6th plate,
(s)he'll have a pretty good handle on it. If not, it means process
control is otherwise poor and (s)he needs to achieve consistency before
practicing the dag.

Just my view. YMMV.

Best regards,

etienne
Received on Mon Aug 23 09:05:57 2004

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