RE: [APML] recommendations for development of tech pan

[Kirk Carbo <kcarbo@lobosservices.com>]

I never have tried dividing powdered developers into portions because I read
that the different compounds used in the developer are probably not evenly
distributed because of differences in grain size and weight.  The nice thing
about B&W photography is that it is very forgiving.  Even if dividing the
powder does produce inconsistent batches of developer, it will probably
still produce good negatives.  I know I keep HC110 around a lot longer than
Kodak recommends and I am sure it probably affects the contrast range of my
negatives, but that's what variable contrast paper or photoshop's curves are
for.

Kirk Carbo

> -----Original Message-----
> From: Chuck Vaughn [mailto:aa6g@aa6g.org]
> Sent: Tuesday, September 16, 2003 9:22 AM
> To: Discussion of Film Astrophotography
> Subject: Re: [APML] recommendations for development of tech pan
> 
> 
> Kirk,
> 
> > D19 is a powder and the entire packet has to mixed so its' useful 
> > shelf life is less.
> 
> This is not required. I weighed out enough D19 to make 16 oz batches 
> for years and it worked fine. To increase the lifetime of the 
> powder I 
> now divide the package up into 8 some sealable plastic bags and store 
> them in the freezer. I just used some that had been in the 
> freezer for 
> nearly 2 years. It had not oxidized.
> 
> Chuck <aa6g@aa6g.org>
> 
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo
> 
_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo