Re: [APML] Black Negs a new developement

["Monte Wilson" <montezinho@bigpond.com>]

Its starting to sound like the developer/development may be the cause. I
know you said you are using fresh stuff and like to make new batches.

Are you using to much agitation, too high a temp, wrong concentration? If
you have a local friend doing d-19 too, send some to them to do it. That way
you can start to eliminate areas of potential trouble.

I know these all sound a bit elementary but I'll be the first to admit that
no matter how careful I am gremlins can get in.

Monte

----- Original Message -----
From: Robert Reeves <reeves10@swbell.net>
To: <astro-photo@seds.org>
Sent: Tuesday, December 11, 2001 4:17 PM
Subject: Re: [APML] Black Negs a new developement


> > thick enough to ruin the film.  I am in the far west suburbs of Chicago,
> on
> > each night I am sure we were in the 60% humidity range.  Is that too
high
> > without a purge?
>
> Thats high enough humidity to NEED a purge, but not so much that it will
> turn the negative completely black.  Before I fabricated the purge system
> for my Schmidt camera, half hour Tech Pan exposures often hit higher
> humidity than that.  The film was open to the air inside the large volume
of
> the Schmidt camera.  It badly reduced image contrast, to the point of
> rendering the exposure useless, but didn't turn TP black.  It was a very
> dark gray but the image was still visible.
>
> Robert Reeves                      reeves10@swbell.net
> 520 Rittiman Rd.                   www.robertreeves.com
> San Antonio, Texas 78209    210-828-9036
> USA                                     29.484  98.440  200 meters
>
>
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