Shiny. I hope that others using Jobo rotary processors for B&W film will comment here but I cannot believe that a Jobo as opposed to hand inversion can be responsible for the issue you mention. If it was then Jobos would carry a serious warning to the effect of: NOT TO BE USED WITH B&W FILM. In fact I have a Rotary Processing Manual in which the author positively advocates a Jobo, detailing his success with it.
Clearly something has changed to give you the problem you mention but while slack developing( process not being followed) may result in a range of problems I have never seen fluffy edge negs listed as one of them.
For what's it's worth the manual in question mentions only one thing re: rotation speed. It is to the effect of not using it at the "F" position( the slow position) as it can give uneven development especially near the edges of the film. The "P" position giving rotation speeds about 70 rpm should be used, giving even development.
My CPE doesn't have F and P speeds but does have slow and fast speeds with the notations of 1&2. 2 corresponds to the fast speed of about 70-75 rpm. I use this for both colour film and colour prints.
I hope you get to the bottom of it and when you do let us all know the cause
I think you may be right, i have been using the Jobo too long with good results - i have always used the slower speed though, never had un-even negatives. I didn't realise the the fast speed was the recomended setting.
I have a number of things to investigate. The negatives in question are mostly from a trip to Santorini in September. I had to replace the battery in my OM-2N almost immediately after i returned, im thinking the meter may have been giving false readings, and over exposing due to a low battery. This could explain why the last couple of films appear to be over developed - even though im using the same developer and times as always.
I have one roll left, the last looks a good stop over. Any recomendations for dev time adjustment?
Ilford gives the times im looking for, i'll keep you posted
When the CPE-2 first appeared, Jobo recommended the slow speed for film and didn't mention a pre-soak. I bought one in Germany in '82 because our landlady reversed her decision to let me develop film in the bathroom and I had to go to a cold basement to develop. I consistently got bad streaking and standing wave and flow patterns from the film reel spokes with Rodinal and Panatomic-X in 35mm and Verichrome Pan in 120, and also with the 2509 reels and 4x5, but not poorer sharpness. I gave up on the Jobo for film and used it successfully for color printing on Cibachrome and Ektacolor.
Originally Posted by Shiny
A couple of years ago I tried the CPE-2 for film again after finding out about Jobo's revised recommendations for faster rotation and a presoak. Panatomic-X and Verichrome Pan were long gone by then, but it worked well this time with Efke 25 and Rodinal + sodium ascorbate. Very even negatives.
However, I can't see sharpness per se being affected by using a Jobo and constant rotation. Edge effects from semi-stand or stand development are another matter.
Last edited by Lee L; 10-29-2007 at 10:05 AM. Click to view previous post history.
I too have an older CPE 2+. It has a "NETZ" which I am assuming is speed of 75 or 0. When set on 75 it turns, when set on 0 it does not turn. I thought 75 was FAST and have been taking that into consideration when developing film -- seldom satisfactorily.
Originally Posted by Shiny
Do you know the speed of your "slow"?
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Originally Posted by Bruce (Camclicker)
There are two distinct and electronically incompatible versions of this processor, the CPE-2 and the CPE-2 Plus. Netz is the power on/off switch, 0 being off. The original CPE-2 had a motor switch with positions 1-0-2, 0 being no motor rotation, 1 slow speed, and 2 high speed.
Here's the scoop from a Jobo web site http://www.jobo.com/jobo_service/us_.../cpevscpe+.htm :
To expand a bit, the CPE-2 had a white mechanical switch shaped like a chicken foot imprint that hit a stop and reversed the motor. That switch was eliminated on the Plus.
What is the difference between the CPE-2 Plus and the older CPE-2?
In 1992, JOBO discontinued the CPE-2 (#4060) and brought out the CPE-2 Plus processor (#4065) as its replacement. They are nearly identical except for a few differences.
1. The CPE-2 had 2 rotation speeds (about 25 and 65 rpm) while the CPE-2 Plus has only one; 75 rpm. Even prior to the introduction of the CPE-2 Plus, we had been recommending use of only the higher speed on the CPE-2.
2. The CPE-2 Plus uses the same motor as the ATL-1000 AutoLab processor. The motor itself is more reliable and uses an electronic sensing system to signal when to change the direction of the rotation. This is more reliable than the previous micro switch. (Sorry, this cannot be upgraded in the older model.)
3. The CPE-2 adds a thermal overload sensor to automatically shut off the heater if it should get too hot, such as turning on the heater without water in the trough. If this happens, you can reset the thermal overload by pressing a switch on the side of the motor head. On the older CPE-2, the overheat condition would require a trip to the repair department at JOBO.
The older CPE-2 processor cannot be upgraded to a CPE-2 Plus. All of the circuitry and even the housing for the two processors are different. Only the trough and bottle rack remain the same.
Jobo says they recommended the higher speed before bringing out the Plus, but the instructions for my 1982 CPE-2 state clearly in multiple places that the slow speed was designed for, and should be used with film. I think this nebulous backdating of the speed recommendation was CYA (cover your posterior) after they disappointed a number of customers like me with regard to film processing according to their instructions in the CPE-2.
Last edited by Lee L; 10-29-2007 at 11:07 AM. Click to view previous post history.
Reason: found the correct info on a Jobo web site
Thank you very much.
My one speed PLUS than cannot date earlier than 1992. That's good to know.
Jim For what its worth and maybe adding to what is an informative correspondence between Bruce and Lee, my manual written by a guy called John Tinsley recommends a pre-soak for Ilford film although Ilford itself doesn't recommend this.
Tinsley says that the pre-soak eliminates the need to shorten dev times compared to Ilford's recommended reduction of 15-20% without a pre-soak.
It would seem that Tinsley experienced no problems with a pre-soak and gives times for Pan F, FP4 Plus and Delta 400 as examples but not any others, although he goes on to mention HP5+ and Fuji Neopan 1600. He lists 3devs: ID11, Perceptol and Microphen.
The only dev he warns against using for rotary processing are: Tetenal Neofin Blue and Red and Paterson's Acutol.
However a word of warning. The book is vintage 1992 and I don't know whether the Tetenal and Paterson devs mentioned may have changed.
I don't know whether this book is still in print but I doubt it. Useful to have if you can get it. It covers E6, C41 and RA4 as well.
I'd concur with others... you have to have pretty DAMN sharp negs and immaculate camera technique to start seeing sharpness differences from your developer or agitation to the degree you suggest.
RE: Pentaxuser's comments;
I believe that Jobo tested and ended up recommending methods essentially the same as Tinsley's. I just found some of the Jobo Quarterly repository that moved, and here's what they had to say about presoaking in 1998:
http://www.jobousadarkroom.com/jq/jq9802.htm and scroll down a bit.
I didn't find the revised methods until a couple of years ago, having given up on the CPE-2 for film in 1983.
Interesting about the Tetenal info. My 1982 manual says "Tetenal Neofin colour developer for colour negative materials is not suitable for rotary processing. The black-and-white Tetenal developers Neofin Red, Neofin Blue, and Neofin Document are however suitable."
Maybe we should publish a new manual with everything stated exactly opposite of the instructions I got with my machine in 1982.
I did find that Tinsley's methods worked for me in a recent test as I stated earlier in this thread. However, I've had a heated darkroom for years and don't need to wait on the water jacket to heat up and slower handling of the CPE-2 compared to stainless tanks. I also have a personal preference for intermittent agitation.