From: rspeirs@javelin.sim.es.com (Ron Speirs)
Subject: Re: E-6 with NO Jobo (Was: E-6 in Jobo)
Organization: Evans & Sutherland Computer Corporation
Date: Mon, 27 Jul 1992 21:54:01 GMT

In article <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.
>
I started doing E-6 about 10 years ago with exactly this setup - stainless
steel tanks and reels.  At that time I had never heard of a Jobo.

>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.
>
>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).
>
Remember that a stainless steel tank conducts heat very well (when compared
to plastic).  I keep a warm-water bath in a tupperware breadkeeper (like a
dishpan but with vertical sides).  In it I have an evaporative cooler pump
running on lowered voltage from a Variac (to keep the water gently moving)
and two "coffee cup" immersion heaters connected to a home-brew temperature
control circuit.  (Yes, I'm using a GFCI breaker if this worries anyone).
There is about 4-5 litres of water in the container, and this much water
has quite a lot of thermal inertia, which makes it quite easy to keep the
water at the right temperature.  To find out what temperature your water
should be, fill your film tank with water and adjust the water bath so
that the water in the film tank is right at 37C (100F).  With a steel tank,
the water bath may be a degree or so higher than 37C because only the
lower part is in the water bath.

Rather than absolute accuracy, the word to remember is consistency.  There
may be other factors that are hard to define (the accuracy of your thermometer,
the mineral content of your water, the pH of your water, your agitation method,
how fast you pour the chemicals into or out of the tank, etc.), but if you are
consistent in these things, you will soon discover (and be able to correct
with minor time schedule tweeks) how your process works.

>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?
>
I use 2 inversions every 30 seconds, with the initial "thump" on a hard 
surface to dislodge air bells.  With this agitation, my first developer is
7 minutes (with 30-second increases for 2nd batch and 3rd batch), and the
color developer is 6 minutes.  These developers are from the Kodak 5-gallon
replenisher sizes, as I haven't bought a 1-gallon kit for many years.  BTW,
don't mix the whole gallon at once.  I would hope directions would be in the
1-gallon kit to mix pint or quart batches.  If they aren't, measure the
concentrates and calculate the appropriate amounts.  

Ron Speirs, Evans & Sutherland Computer Corp., Salt Lake City, Utah


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