Re: [APML] Self hypering camera from Taurus-tech?

[Jerry Lodriguss <jml@astropix.com>]

At 05:28 PM 9/30/2002 -0700, you wrote:
>According to Wallis & Provin in A Manual of Advanced Celestial Photography,
>straight dessication and nitrogen soaking does have a definite effect in
>improving film sensitivity/reducing reciprocity failure. The magnitude of
>effect in their Table 10.2 is only graded into slight, effect(ive), and very
>effective, plus avoid, but  they rate nitrogen soak or bake as Effective;
>forming gas soak or bake is Very effective.
>
>In another place they say that dessication and oxygen removal are essential
>in the hydrogen-sensitizing process and imply that this holds for any type
>of sensitization.


I think the level of desiccation and oxygen removal that Wallis and Provin 
are talking about is on an entirely different level than what this camera 
will provide.

Removing the moisture from the air will certainly help prevent the emulsion 
from absorbing moisture and creeping, however, that packet of desicant in 
the camera is not going to pull any moisture out of the film's emulsion 
that was present when it was manufactured.

That is what true low vacuum and/or baking accomplishes, it removes the 
moisture from the emulsion.  This camera is not going to do that, so no 
hypering is going to take place.

This camera is not going to provide real desiccation and nitrogen soaking.

This camera could be very helpful for shooting film that is already 
hypered, and for shooting non-hypered film in a humid environment.

However, I wonder how critical the manufacturing tolerances can be for a 
camera that looks like it is make out of plastic.

Jerry

Astronomical photography: http://www.astropix.com




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