Re: KODAK EKTACHROME IR FLIM

[Helmut Faugel TE <htf@xxxxxxxxxx>]

On Tue, 10 Jun 1997, George L Smyth wrote:

> Willem-Jan Markerink wrote:
> > 
> > I got a cold blue cast when using #8, the only Cokin-P size filter I
> > had at that time. #21 was too warm/reddish, but I recently added #12
> > and #16 to my filter range....:-))
> 
> I also got a blue cast with the #8 filter used with the old film, but I
> believe that that was because the film had been at room temperature too
> long.  Could this have been the case?

The reason for the blue cast than you use #8 filter is that yellow sensitive
layer get more light than the other because it is also sensitive to shorter
wavelenghts too.

Storing the film at room temperature usually reduces the sensitvity of
the IR-layer (the dye causing the IR-sensitvity is very unstable at
higher temperatures), but I do not know what happens to exposed material.

This is not IR but maybe interesting:
My father was know for photographing very much. A film would last for
at least two years (I changed this by giving him a Yashica T 5 as a
present, at least a 1000% increase in film use ;-)). The pictures
he got looked like this: The first (longest time between exposure
and processing) usually showed an extrem red cast, which was impossible
to get rid off, the last one showed a slight blue cast (this a possible
desensibliation of the red sensitive layer because the film was stored
at high temperatures). Any comments on this behavior?


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Helmut FAUGEL                       |  Tel.   : +49 / 089 / 3299 2245
Max-Planck-Institut f. Plasmaphysik |  Fax    : +49 / 089 / 3299 2558
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D-85748 Garching bei Muenchen       |
Germany                             |
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