Re: [APML]: improving Tech Pan development

[Alfredo Zanazzo <alferd@mbox.lol.it>]

Robin Casady wrote:
> 
> 
> Joseph O'Neil wrote:
> 
> >  -with reguards to constant rotation -
> >   That is an interesting idea.  I just may have ause for my old rock
> > tumbler!  It is designed to turn continusly at low speeds.  I think I
> > will try something out, and let you know.  thanks for the idea.
> 
> Something to think about: If you roll a developing tank that has film on
> a spool, the film on the outside may get more agitation than the film
> near the center. Also, a consistent agitation pattern may set up a
> consistent pattern of eddies in the developer, causing inconsistent
> developement.
> 
> Motorized drum development works for sheet film and prints because the
> film/paper is flat against the outside of the drum; there is nothing to
> cause eddies.
> 
> When developing b&w film I would try to be vary my method of agitation
> while maintaining a consistent amount of agitation from batch to batch.
> --
> Robin Casady
> http://www.scruz.net/~rcasady/
> -----------------------------In fact I use 4X5 fil sheets,

If you have read carefully my message, the rotation involves several
different moves; inversion of direction, tilt due to inclined plane,
vibration due to friction on the surface of the pot.
I doubt that with your hands you could evr produce such a varying
moves of developer on film, and specially with the same amopunt for
every process.
Anyway my results speak: I have tried both methods and electrical rota
tion it is better!
If yopu have tried for instance to develop colour paper handly in basins
you NEVER get contrast and saturation equal to a mechanical agitation
and specially the continuous tilting of the chemicals produced by the
pump.
This applies to 35 mm film as well, although it is less critical than
with film sheets.
I speak about my experience, everybody could have different experiences!
Ciao
-- 

--
Regards, Alfredo Zanazzo ( alferd@mbox.lol.it )

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