Another cute IR book added to the pile!

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

Dear gang,


Today I visited the Fotografica Beurs in Houten, Holland; Europe's 
largest indoor photographica show.

My main 'hit' was within 100m from the entrance; I found "Infrared 
Radiation" written by Antonin Vasco in 1963, Czechoslovakia, 
translated into English in 1968, published by Iliffe Books, Londen.
(I just love the smell of those old books....8-))

Stuffed with formula's I thusfar only could find spread over several
books, and it shows Herschel's first IR-photo, a spectral analysis
of the sun in 1840.

Some other interesting details:

The first commercial IR-sensitive photographic emulsion was launched 
in 1905, by Hoechst, Koening and Phillips, using Dicyanine. 
Sensitizing power up to 800nm, but it did not become commonly used 
because it did not prove sufficiently stable in air.
It was not until 1919, after WWI, that a new emulsion was created by
Kodak, using Kryptocyanine; senstitive up to 780nm but more stable
in air. 
In 1925, Neocyanine was introduced to the market by Kodak. It was 
prepared by H.T. Clark, and has a sensitizing power up to 880nm. By 
hypersenstizing these layers in a cold water bath or an ammonia bath, 
it has been possible to achieve sensitivity out to 1163nm(!). 
In 1928 Agfa introduced Rubrocyanine, a chemical equivalent of 
Kryptocyanine, and a year later Allocyanine, chemically identical 
with Neocyanine.
In 1932, several sensitizing dyes of the tricarbocyanine series were 
prepared. These dyes have superior properties adn are still in use 
today [1963].

There is a nice list of IR-emulsions available at that time, from the 
following companies:  
- Agfa Gevaert A.G. (Leverkusen, GFR (? see note ORWO below)
- Ferrania (Milan, Italy) 
- Guilleminot R./Boespflug Cie. (Paris, France) 
- Ilford Ltd (Ilford Essex, UK)
- Konishiroku Photo Industry Comp. (Tokyo, Japan) 
- ORWO VEB Filmfabrik (Wolfen, GDR (? I almost translate this with Gross 
 Deutsches Reich, but this is in 1963....weren't the Germanies not 
 already split by then?)
- 'USSR' ("Infrachrom", three emulsions

A more stunning fact is that Kodak did not supply just one b&w film from 
Rochester, but two b&w emulsions; and several more from Kodak Ltd 
(Londen, UK) and Kodak-Pathe (Paris, France).
The two emulsions from Eastman Kodak in the US are the 
- "Kodak Infra-red Film IR 135, 35mm in cassettes for 20 shots each" 
- "Kodak Infra-red Film (in sheets)" [both sensitivity up to 870, peak 800nm] 
- "Kodak High Speed Infra-red Film (H5218); 16mm HIR 430, 35mm HIR 
421-1 & HIR 417"
Development times for the latter series is also different than for the first 
two; as well as the darkload requirement.

Kodak France also produces H5218, and with Kodak UK they both produce 
IR-plates.

Another cute detail: AEG IR-imaging tubes of that era were made in
Prague, country of origin of the author of this book. The same AEG
tubes that are claimed to have been used in Rollei night vision
units (my Rollei unit oddly enough shows a VARO tube, made in the
USA). It's a strange, small world....8-))

All in all a fruitful visit to this photographica show....:-))
(no, I did not buy more gear....;-))

--
Bye,

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     _/  _/ illem    _/     _/ an    _/  _/  _/ arkerink
                     _/_/_/  



      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]
--
Bye,

       _/      _/       _/_/_/_/_/       _/_/_/_/_/
     _/  _/  _/               _/       _/  _/  _/
     _/  _/ illem    _/     _/ an    _/  _/  _/ arkerink
                     _/_/_/  



      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]

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