From: Jeff Sumner (jdos2@mindspring.com)
Date: 10/08/02-06:39:49 PM Z
Sigh. I was hoping I wasn't going to have to actually provide
*citation.* Here goes. (me: moving i-Tunes to something better-
shuffling off to the distant bookshelf)
The Tome:
"The Daguerreotype (Sub: Nineteenth-Century Technology and Modern
Science)
M. Susan Barger and William B. White, The Johns Hopkins University
Press, 1991.
The specific reference to varnishing... (thumbing, thumbing) On page
33, figure 4.3- View of the Central High School, Philadelphia, by John
Saxton, though I got the information about it being varnished from
another book, borrowed from the library, of 60's vintage (it still
suggested thiourea as a Daguerreotype cleaner!)
Affects from varnishing were known to be reduction in contrast, severe
color shifts, or the image will simply disappear.
The Above mentioned book is in print (The Daguerreotype) and has all
sorts of electron micrographs and other information about the history,
the process, the history of the process, the process of history...
Sorry, got carried away there with my wish that Mac Mail would work
with LaTeX documents for bibliography purposes.
Sigh. After all that, crank iTunes to "The Lemon Tree," listen to the
Trio go, and ...
If anything interferes with the dialectric constant of air,
Daguerreotypes simply look different. Usually worse. I think it
completely amazing that the daguerrian process works *at all* and that
it isn't more sensitive than it is. "The Daguerreotype" mentions that
daguerrian images can be processed in regular developers- they end up
looking very different. Amazing. Silver, iodine, perhaps some bromine
and mercury, salty water and an aluminum rod (instead of fixer), some
dissolved gold chloride, heat, and one has an archival process of
incredible depth and subtlety. These things still impress the heck out
of me. All that based on different reflectivity/refractivity of little
tiny silver bumps.
JD
On Tuesday, October 8, 2002, at 08:17 PM, David Eastman wrote:
> Jeff, Christopher, Everyone,
>
> Where can I get more information on the dag
> "interfererence image" and refractive index...?
>
> What happens when one uses an (unsuccessful) varnish?
>
> Perhaps my idea is way off, (no experience here) but I
> am curious about what would be the result of the 3
> different treatments... how would they differ?
>
> 1.Gelatin
>
> 2.Collodion
>
> 3.Don't know what its called, there are probably
> several types, but what about the thin (low tac?)
> films that are used to cover watch dials or other
> "windows" or high quality lamination? Some are good
> enough to go unnoticed until dirt builds up around the
> edges. I had one covering the dial of something for
> almost two years before I noticed it!
>
> Curiosity Guessing!
>
> Ray
>
>
> --- Jeff Sumner <jdos2@mindspring.com> wrote:
>> I know all sorts of varnishes have been tried,
>> mostly unsuccessfully,
>> but the oldest recognized American Daguerreotype was
>> varnished- the
>> image is still visible.
>>
>> From what I understand, because of the way
>> Daguerreotypes work, with
>> little bumps of silver forming an interference
>> image, anything that one
>> does to change the refractive index is going to
>> affect images.
>>
>> JD
>>
>>
>>>
>> JD
>> 2001 Moto Guzzi V-11 Sport
>> 1999 Triumph Trophy (Shop Bike) 1200
>>
>
>
> __________________________________________________
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>
JD
2001 Moto Guzzi V-11 Sport
1999 Triumph Trophy (Shop Bike) 1200
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