Re: [APML] TP woes - the verdict

["Jim Janusz" <jjanusz@dc.rr.com>]

I can add one thing to this.

"4) Heavy dew is very bad and hard to protect the film from."

Don't even bother to try high vac hypered in heavy dew, even with nitrogen
flowing.  Put away the film, it's a waste of film and effort.

I have tried this and the results were very bad, I even ruined a 4 inch
wratten filter.

Jim

----- Original Message -----
From: "Chuck Vaughn" <aa6g@aa6g.org>
To: <astro-photo@seds.org>
Sent: Tuesday, April 23, 2002 2:33 PM
Subject: Re: [APML] TP woes - the verdict


> Grant,
>
> > What exactly do you mean by 'exposed to humidity'.
> > I ask this because...yes it gets humid around here.
> > But how much humidity is too much for tech pan?  Is the
> > tp unaffected until dew starts forming?  Or can it fog simply from
> > moist air?
>
> Thes are interesting questions. My experience is different with
> high and low vacuum hypered TP. I did not have nearly the problem
> with Lumicon low vacuum hypered film as I did with my high vacuum
> hypered film.
>
> So let me divide it into the two types.
>
> Low Vacuum
>
> 1) Light dew is not a problem.
> 2) Heavy dew begins to fog the film.
>
> High Vacuum
>
> 1) Film is okay only with no dew at all.
> 2) Light dew begins to fog the film.
> 3) Wind with moderate humidity really fogs the film.
> 4) Heavy dew is very bad and hard to protect the film from.
>
> Chuck <aa6g@aa6g.org>
>
>
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