Re: [APML]: Hypering thread ...

[Jerry Lodriguss <jml@astropix.com>]

>Hence the interest in seeing if the moisture can be removed in a 'pre-hyper'
>stage, so that hypering itself may be conducted in a more pure environment.
>There were strong indications from Experiment 2 that a substantial
>proportion of moisture can be removed in a in a pre-hyper stage, leading to
>a much smaller pressure rise during actual hypering.  Experiment 3 will go a 
>stage further and I would expect to see minimal pressure increase during 
>hypering.
>
>Will a minimal pressure rise during hypering mean a more sensitive film?
>I haven't a clue, but it's certainly an interesting enough area to pursue - 
>that's where I was hoping friends on the list might be able to help out.


Philip, I believe you are right about all of this. The problem is that the
release of the water seems to be gradual and not all at once.  So you will
have to try to entirely recalibrate your hypering process. What will the
fog mean now if you get some fog from the baking process to remove the
moisture, and then fog from the hypering in forming gas?

I'm not trying to discourage you from experimenting, but you should take a
look at the voluminous literature that is out there already in this field
(see the bibliography in A Manual of Advanced Celestial Photography).
Perhaps you won't have to re-invent the wheel again, I would really suspect
someone has already investigated this exact subject.

If you are that REALLY concerned about maximum OPTIMUM hypering, why putz
around with this low vacuum hypering anyway. Why not just bite the bullet,
and get the high vacuum pump like Chuck has? Hey, it's only money! <G>

I asked Brad Wallis about this and this is what he said:

>That is why I used to purge for 48 hours in N2 and then bake in N2 for
>24 hours before letting H2 in the tank ...  

You might want to try this if you don't get a high vacuum pump.

Jerry 
email: jml@astropix.com 
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