Re: [APML] TP woes and questions

["John C. Mirtle" <spampit@shaw.ca>]

Roland,
    Hypered, unexposed tech pan should have a base fog level of somewhere
around 0.3, or 50% transmission. This will vary with high or low vac hyper
and a bunch of other stuff, but it's a good rough guide. As has been
mentioned, it slowly darkens with age, and Lumicon were variable with their
fog level. Most of the film I bought from them (I stopped about 12 years
ago) was pretty dark. Maybe the "new" Lumicon will be a bit more consistent
and not quite as dark? It would be 2.5 years younger....

John Mirtle
Calgary, Ab. Canada

----- Original Message ----- 
From: "Chuck Vaughn" <aa6g@aa6g.org>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Saturday, October 04, 2003 9:03 AM
Subject: Re: [APML] TP woes and questions


Roland,

> So, did I just overdevelop the film, or did this roll have a problem?
> I'm thinking of pulling out another roll out and cutting a small piece
> to develop at shorter times just to see how dark the unexposed film
> gets.  Ideas?

Develop a piece of film that has never been in a camera to see if that
comes out right. Develop for 10 minutes. The unexposed frames should
only have light fogging especially if developed in HC-110. When you get
that result then we can go from there.

Chuck <aa6g@aa6g.org>

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