[Leica] Re: Xtol newbie

[Rolfe Tessem <rolfe@ldp.com>]

> Date: Wed, 3 Oct 2001 05:05:29 -0400 (EDT)
> From: Rei Shinozuka <shino@ubspainewebber.com>
> Subject: Re: [Leica] Re: Xtol newbie
> Message-ID: <200110030905.FAA17099@tigercat.nyfir.pwj.com>
> References: 
> 
> regarding the xtol "100ml rule," it's interesting that Anchell and Troop
> (as referred to by Guy) in the _Film Developing Cookbook_ page 31 state
> that for full development of all images on the roll, you need to use
> 250ml of undilute developers: XTOL, D-76, MicrodolX, 500ml for D-76 1+1,
> 1000ml D-76 1+3.  i have a densitometer and i suppose the responsible
> thing is to try the recommendation versus the 100ml and vs 75ml.
> however, ONE LITER of solution PER ROLL is a very bulky prospect indeed!!
> it just about precludes processing more than one roll at a time.
> 
> Guna Sengalrayan brings us to the jobo site, where:
> 
> http://www.jobo-usa.com/jq/jq9701.htm
> 
> talks about xtol in the jobo processor.
> their test indicated that for 1+1 dilutions, and AGFA film,
> you needed 200ml of stock solution (400ml total) per roll, but
> 100ml of stock was sufficient for kodak, ilford and fuji films.
> this article did not test dilutions beyond 1+1.
> 
> i use jobo tanks, but don't rotary process the film anymore.
> 
> finally, the jobo site interestingly recommended AGAINST a water
> prewet, which i've been doing since i started doing film developing.
> (recommended by fred picker!)

I've spoken to Jobo about this. The only reason they recommend against
it is that Kodak did extensive testing on rotary processors (something
the company had never done previously) before it released Xtol and
therefore had published times that were good *without* prewetting.
Rather than second-guess the Kodak research, Jobo simply went with the
Kodak data which had no prewet. 

The prewetting does no harm -- you just have to establish your own
times, which are normally the same as the inversion tank times minus
prewetting. I use a Jobo Autolab 1000 and on this processor there is no
way to prevent the machine from running a prewet step, so I just live
with it and of course it works fine.

Rolfe Tessem
NYC
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