From: goldis@news.weeg.uiowa.edu (Al Goldis)
Subject: Re: E-6 with NO Jobo (Was: E-6 in Jobo)
Organization: University of Iowa, Iowa City, IA, USA
Date: Mon, 27 Jul 1992 02:14:35 GMT

In <211@metran.UUCP> jay@metran.UUCP (Jay Ts) writes:
>Now, I have a question for all you E-6 experts.  I have used the Hobby Pac
>a few times, and want to improve on quality and cost-effectiveness.  This
>means going for Kodak's gallon size E-6.  But I don't have a Jobo processor;
>I just use a water bath and a stainless steel tank and try to keep the
>bath around 105 deg. F.

>Does anyone have enough experience with this method to warn me of some of
>the pitfalls, or better yet, offer some advice?  I would love to hear from
>you, since I am currently very antsy about investing money in the E-6
>chemistry to try it out for myself.

Like Nike says, "just do it".  I'm sure you are plenty competent to
achieve good results.  Many people seem to have phobias about color
processing that I think are unwarranted.

>How carefully do I *really* have to control the solution (especially
>1st developer) temperatures?  I keep reading .1 or .5 degree.  What
>happens if the temperature slowly (and monotonically) varies from
>say, 106 to 104 degrees during the 5 minutes of 1st developer?  I
>just tried that with the Hobby Pac, and can't see any problem (no
>color shift or crossover apparent, anyway).

First of all, the Jobo I use doesn't really maintain temperature that
well.  Second, you don't have to be as exact as you think.  Here are
a few temperature tolerances for small tank processing:

First developer   100.4F +/- 0.5F   38C +/- 0.3C
Reversal Bath     92F to 102F       33C to 39C
Color developer   100.4F +/- 2F     38C +/- 1C

As you can see, it's not as fussy as you fear.  The most critical
solution is the first developer.  While you want to be as close as you
can, I don't really think a larger 1st dev. temperature variation will
make much difference.  I could be wrong, but it seems to me that the
main reason for 1st dev. accuracy is consistent density.  If you think
about what the 1st dev. does, it doesn't seem like small time/temp.
variations will do much besides change the overall density (wild
variations aside).  I would expect variations in the color developer
to be more dangerous and yet the temperature is not as fussy.  Well,
what do I know? ;-)

Anyway, the Jobo I use normally drops a couple degrees F during the 1st
developer.  No big deal, you just compensate (with temperature
drift-by or extend the time).  I know what temperature and time I need
to use to get the results *I* expect.  That's why I suggested you run
some test rolls before using "real" film.  You will need to see how
things work in your system so you can compensate for variations.
(Also, your hand agitation will not be the same as everyone else.)

>Also, if I agitate every 30 sec. with 5 inversions, is there a correction
>for development (and other) times?  Or should I just use continuous agitation,
>like the Jobo users?

There are differences in the process times between using a Jobo and a
small tank with inversion processing.  For instance, first developer
time with a Jobo is 6.5 minutes and small tank is 7 minutes.  If you
get the Kodak gallon kit, it will have all the information you need.
--
Al Goldis           alan-goldis@uiowa.edu
"Pictures are moments truth, touched by light, that show character."
                          --Annie Griffiths-Belt