Re: [Rollei] Kodachrom in Germany

[Richard Knoppow <dickburk >]

At 01:34 AM 02/02/2002 +0100, you wrote:
>Yes, Kodachrom without the "e". Here's from an add in Photofreund Jahrbuch 
>1938 (printed in 1937):
>
>...und nun auch farbig. KODACHROM, der höchstempfindlische Farbenfilm für 
>Tages- und Kunstlichtaufnahmen ("Kodachrome" Type A). Immer zu belichten wie 
>ein Panchromatischer Film 13º/10 DIN. Ohne Filter, ohne Raster, ohne Korn!
>
>(and now even color. KODACHROM, the high sensitive color film for Day- and 
>Lamp light ("Kodachrom" Type A). Always exposed as a Pan-chromatic film 
>13º/10 DIN. Without filter, witout raster, without grain!
>
>(Didn't know how to translate "raster" to english.
>
>I don't know if a film of 13º Din, 16 Asa, is high sensitive with todays 
>standards though. :-)
>
>/Patric
>
>
  The first Kodachrome would be around 8 or 10 ISO, tungsten film was a
little faster, maybe 12 ISO.  
  However, compared to the other processes around at the time this was not
so slow. One shot cameras were slower, depending on the type of film they
were balanced for. The fastest one-shot cameras reached about ISO-12 in the
late 1940's. 
  I wonder if Kodak had set up a European processing plant for Kodachrome
somewhere. 
  Kodachrome became available as 16mm motion picture film late in 1935 in
the US. The original developing process was enormously complex and depended
on the controlled penetration of a bleach into the emulsion layers. After a
couple of years the process was changed to one relying on differential
re-exposure. Also complex but much easier to control than the original
process. In no longer remember the date of the change, but it was only a
year or two after the commercial introduction of the film. 35mm slide film
and roll and sheet sizes followed. At one time Kodachrome was available in
sheet sizes up to and including 16 x 20 inches. 
 Agfa announced Agfacolor at about the same time as Kodachrome. However, it
was not widely sold and I am not sure it was available in the US. There was
a previous Agfa color film, I think also called Agfacolor, which was an
additive type film using a reseau of dyed starch. Not to be confused with
the later film which was an incorporated coupler multilayer chromogenic film. 
  I think Kodak may have known of the research being done on color at Agfa.
One of George Eastman's wishes was for Kodak to devise an easy to use color
film. They really didn't beat Agfa to it. It took Kodak some years to find
an alternative method of anchoring the color couplers in their respective
emulsions. Agfa's method was to attach the couplers to very long chain
polymers. Kodak's method was to incapsulate them in resins which allowed
the penetration of developer reaction prducts but did not allow the escape
of the coupler or the dye it produced. I am not sure which system is in use
now but think its the Agfa system. Most developers for the Kodak system
required the use of alcohol to help penetrate the resin. These films and
papers also looked hazy or greasy until thoroughly dry. 
  Kodak's first incorporated coupler film was Kodacolor, commercialized
about 1942. I think both Agfa/Ansco and Kodak made color aerial film using
both systems, since the Agfa patents were seized, along with all other
Agfa-GAF property, at the outbreak of WW-2.
- ----
Richard Knoppow
Los Angeles, CA, USA
dickburk  

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