David Nebenzahl wrote:
On 1/24/2004 9:04 AM Jean-David Beyer spake thus:

David Nebenzahl wrote:



On 1/23/2004 8:03 PM Jean-David Beyer spake thus: I'm guessing
that the problems associated with constant, invariant agitation
in this device (Jobo) must have something to do with the interior
geometry, topology or hydrology of the gizmo, as I never have
problems with my rotary processor, which is the Beseler Unidrum
(for 4x5 and 9x12). There must be something inside the Jobo--some
baffle or something else in the flow stream--that causes
standing-wave patterns, eddies if you will, that lead to these
"road ruts".

I disagree. If there were an _inherent_ problem to the Jobo
processor (more precisely, its tanks and | or reels), then
_everyone_ would get these problems, and I do not. Many people use
them successfully, and some even use their fancier reel-less tanks
for negative processing with success. [...]

The _only_ time I got what I might call road ruts was the stripe
parallel to the 5" edge when using the obsolete pre-2509N sheet
film reels. These have been discontinued a decade or two ago. By
now, I would have supposed people would have either upgraded their
tanks and reels or given up rotary negative processing.


So you're saying that anyone who experiences problems such as those
described by the OP must be using these old reels? Do we know what
kind of reels he's using?


I am not saying that, because I know enough about making dogmatic
statements: the most important of which is that the more dogmatic I get,
the more likely I am to be in error. (Be careful: do not step in the dogma.)

What I am saying is the problems are _not inherent_ in the Jobo system,
since I, among others, get no road ruts (even if carefully measured),
and without heroic measures to ensure their absense.

So it must be something the others are doing. While it is possible that
all those people (however many that may be) are either very sloppy
processors using too little chemistry, people who are trying to develop
negatives in print drums, using old reels, _or something else_, but I
have no clue what the something else might be, and I doubt it can all be
attributed to sloppy processing.

I mistrust those who say to rotate the processor 90 degrees to change
the magnetic fields though. They are either joking, or egregeously
ignorant. It happens that my processor is usually lined up along an
East-West axis (roughly; i.e., parallel to White Street in Shrewsbury,
NJ, but I have used it at 90 degrees to that and it matters not).

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 9:50pm up 18 days, 9:15, 5 users, load average: 2.24, 2.13, 2.10