B&W Rotary Processing resources

Matthew Cherry · Jul 26, 2012

Hello all, me again!

I'm waiting for my color chemistry to arrive and thought I'd give the jobo a try on some black and white film this weekend. I'm trying to locate a good resource (such as the Massive Developer Chart) for rotary processing. I've developed quite a bit of B&W film, both 120 and 4x5) but I've always done it either in SS tanks (for the 120) or trays or deep tanks (for the 4x5). I use a variety of films and developers, but for this test, I think I'm going to settle on HP5+ and HC110. Maybe some Tri-X with HC110 as well. I may even to some Tmax in Tmax developer. Ok, maybe some Delta 100 in DDX...

But that's it, I swear.

Any resources for dev times in a Jobo (using the CPP2 with lift) would be great!

Bob-D659 · Jul 26, 2012

Can't remember for sure, but I think the dev instructions mentioned 15% less time for continuous agitation. See the instructions for your favorite developer.

nworth · Jul 26, 2012

I don't remember the exact figures either, but the Jobo times are somewhere between the continuous and intermittent agitation times - somewhat closer to the intermittent time.

Andrew O'Neill · Jul 26, 2012

Will you be printing on photo paper?

pentaxuser · Jul 26, 2012

It seems to depend on developer. Koak's times for Xtol show very little change and for many films, both Kodak and Ilford films, no change at all between inversion and rotary.

pentaxuser

Pasto · Jul 26, 2012

For TMY-2, I find that the development times for rotary processors given by Kodak are spot on (at least with Xtol).

Matthew Cherry · Jul 27, 2012

Yes Andrew, at least all the B&W stuff get's wet printed in my darkroom.

RalphLambrecht · Jul 27, 2012

pentaxuser said:
It seems to depend on developer. Koak's times for Xtol show very little change and for many films, both Kodak and Ilford films, no change at all between inversion and rotary.

pentaxuser

tha's my experience too...little or no change(difference!)

Kirk Keyes · Jul 28, 2012

Search Google for the Jobo Journal of Rotary Processing. There's several years of issues out there so look for them.

Sirius Glass · Jul 28, 2012

Bob-D659 said:
Can't remember for sure, but I think the dev instructions mentioned 15% less time for continuous agitation. See the instructions for your favorite developer.

The 15% time reduction is a really bad idea. I learned the hard way with several films and several developers.

The second sentence of the quote is the correction path. Follow the rotary development instructions from the manufacturer.

Rolfe Tessem · Jul 30, 2012

Jobo's recommendation (back when they were an analog company) was that a five minute pre-wet compensated almost exactly for the continuous agitation. Or, to put it another way, if you use a five minute pre-wet you can use the exact times published for inversion processing with intermittent agitation. In fact, the automatic Jobo processors all build in a five minute pre-wet.

Over hundreds (possibly a thousand) rolls, this has proven true in my experience.

The confusion results from the fact that when Kodak came out with Xtol, which was after rotary processing became established practice, the company went to the trouble of testing. It then published times for rotary processing WITHOUT the pre-wet. This is why those times are 15% shorter, but I see no good reason not to do the pre-wet. It slows down the times to become more manageable in some circumstance and also allows you to use all the published times for virtually any film/developer combination with confidence.

Keith Tapscott. · Jul 31, 2012

This link might be of interest.

http://www.jobo.com/jobo_service_analog/us_analog/instructions/instructions_process_b-w_film.htm

Roger Cole · Jul 31, 2012

Rolfe Tessem said:
Jobo's recommendation (back when they were an analog company) was that a five minute pre-wet compensated almost exactly for the continuous agitation. Or, to put it another way, if you use a five minute pre-wet you can use the exact times published for inversion processing with intermittent agitation. In fact, the automatic Jobo processors all build in a five minute pre-wet.

Over hundreds (possibly a thousand) rolls, this has proven true in my experience.

The confusion results from the fact that when Kodak came out with Xtol, which was after rotary processing became established practice, the company went to the trouble of testing. It then published times for rotary processing WITHOUT the pre-wet. This is why those times are 15% shorter, but I see no good reason not to do the pre-wet. It slows down the times to become more manageable in some circumstance and also allows you to use all the published times for virtually any film/developer combination with confidence.

Exactly what I do and my experience mirrors yours and Jobo's recommendation - five minute pre-wet, which also gets the film stabilized to the same temperature the developer will be, and use the regular times for small tanks as starting points. Across multiple films from multiple brands and with multiple developers from different companies they are consistently very similar to results with small tank inversion processing. Of course you need to work out your own times anyway, but that's the place to start.

B&W Rotary Processing resources

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