Jobo CPE-2 - slow versus fast speed

[Don Wallace]

I have a Jobo CPE-2 which I use for 4x5, on the higher speed. I am having a problem with some of my developing times getting below 5 minutes which I have read is not recommended for rotary processors. I can't increase my dilutions any more or I will have too much volume of developer for the tank. So, the lower speed seems to be the way to go. Do any of you use the lower speed on the CPE-2? If so, do you happen to know what percentage of increase in development time would give a rough equivalent?

 

[Lee L]

When I first got my CPE-2 in 1982, Jobo recommended the slow speed for developing film. I had problems with standing waves/very uneven development with 4x5, 120, and 35mm at the slow speed. Many years later, after I found out Jobo had changed to recommending the higher speed, I tried it for 35mm and the problem didn't recur. I wouldn't recommend the slow speed for film. I'm not sure how much the slower speed would slow the development process, as you're changing constant agitation to constant agitation.

(I haven't run more than the one test roll in the Jobo at the higher speed, as I originally bought it only to overcome a problem with an unheated darkroom, and have had a heated space since a few months after that.)

Lee

 

[Jim Chinn]

I use a CPE-2 for 35,120 and 4x5 and have always used the fast speed. Never had a problem. With regards to a 5 minute development time I had read somewhere that one should presoak the film for shorter times in a JOBO.

What is the film and developer combo you are using?

 

[Lee L]

The Jobo Quarterlies actually recommend a 5 minute presoak as a way of slowing the developing time so that rotary times with a majority of developers match the standard small tank inversion times more closely. In other words, a 5 minute presoak slows the process. This came from Jobo technicians in Germany.

I'm trying to find a link to the Jobo Quarterlies online. They have been coming and going over the years, and I can't find the last reported link to them, which was here on APUG, but the search for this site doesn't bring up the needed post. I'll keep looking and post back here if I have success. Maybe someone will beat me to it.

Got it: http://www.jobo.com/jobo_service_analog/jq/

There are several years' worth, and the advice changed over time as new ideas and methods were developed, so it pays to read through them.

Lee

 

[bdial]

My experience with slow vs fast on a CPE is similar to Lee's in that I got uneven development with slow, and no problems with fast, processing 4x5. I have not had problems with increasing the volume a little to accomodate the desired dilution.

 

[pentaxuser]

Lee's and bdial's findings are backed up by John Tinsley who wrote a book on rotary processing in the 1990s and used the Jobo processor on a small commercial scale. He believed that the pre-soak pretty well counterbalanced the shorter processing times so he used the normal inversion times with the Jobo processor.

A worthwhile book if you can get hold of it

pentaxuser

 

[Mick Fagan]

I have a CPE2 early 2 speed model with lift, which I bought new in the eighties. I have been processing film in it since then, always on the slower speed.

On Monday evening I developed two 4x5" sheets of FP4+ using D76 1+1 at 19.6ºC for 14'45".

I never do a pre-soak with film, never have, never will, for any normal processed film.

When I develop C41 4x5" film, the first developer bath is for 3'15", this is much shorter than what you have mentioned.

You probably don't wish to know just how beautiful my negatives are.

My regime is simple, when first putting in the first solution I run the machine at the high speed, pour the solution in, then by the time 15 seconds has passed, I switch to the slower speed.

I use the fast speed in only to ensure that the film gets covered in developer as fast, and as evenly as possible.

135, 120 and 4x5" sheet film, are all started off the same way, regardless of how long or short my first solution time.

I'm not sure where in the world you are, or how your water supply is, but a pre-soak could be causing you problems. In the late summer months in our water supply lakes, the authorities add a flocculant to the water, this then makes the precipitates in the water drop to the bottom of the reservoir.

I had some streaking problems and the occasional uneven development happenings with colour paper development. I was using a pre-soak to bring the paper and drum up to temperature, dumping then developing.

The Agfa technicians after listening to my complaints and procedure told me to stop doing a pre-soak. I did and the problem went away. Their reasoning was that the precipitate the water authority was using, interfered with the evenness of developing. I believe they were spot on, never had a problem since. They also mentioned that pre-soak for film wasn't recommended as the conditions with either emulsion types was about the same.

When I'm doing large batches of B&W film, I have sometimes upped the temperature to 26ºC and run the developer bath for 5'30". Once again D76, but undiluted, I call it my speedi-brew

One thing I have to ask is this, are you developing 6 sheets at a time or 4 sheets?

I have only once developed 6, 4x5" sheets to a reel, I had uneven development. This was last year when I was testing a couple of lenses.

Mick.

 

[Don Wallace]

Nick says "You probably don't wish to know just how beautiful my negatives are."

Of course we do!!! Don't be silly.

Seriously guys, thanks for the responses. Here is my procedure:

FP4 @ 68F/20C

all of the following steps are in the Jobo, at high speed
- pre-soak 1 minute
- develop for 5 minutes or more in HC-110 dilution E or F
- wash for 1 minute
- fix for 2 minutes (or more)
- wash 1 minute
- HCA 2 minutes

I do a final 5 minute wash by taking the tank off of the machine and using a hose.

My skies/blank walls, etc., always have areas of inconsistent density. I never develop more than 2-3 sheets at a time.

 

[Jeremy]

Don, you might be experiencing developer exhaustion. With HC-110 Kodak says you need 6mL of syrup (US bottle) for each roll of 35mm or 120 or each sheet of 8x10 film. Extrapolate down and you'd need at least 3mL of syrup for 2 sheets and 4.5 for your 3 sheets.

So I'm curious as to what tank you're using to develop these sheets and how much syrup/water you're using.

 

[Lee L]

Jobo recommends a full 5 minute 'pre-wet' for best development uniformity, except for Xtol, for which they recommend no 'pre-wet', depending on the year. (Not sure about alternate Tuesdays.) Perhaps try a test roll that way.

From: http://www.jobo.com/jobo_service_analog/jq/jq9802.htm#3982

To Soak or Not to Presoak

By Ken Owen

Recently, on the internet, we have seen questions regarding black and white (BW) rotary processing, particularly in regard to Kodak’s Xtol developer. Participants in the internet newsgroup rec.photo.darkroom are quick to point out that we at JOBO recommend that all conventional BW films should be processed using a 5 minute presoak, except for Xtol, but there seems to be a fair amount of confusion regarding the reasoning behind the presence or absence of a presoak.

The story goes all the way back to the earliest days of JOBO here in the USA, about 16 years ago. At that time we wanted to be able to provide a simple starting point for BW film processing. Yet, we knew that the constant agitation of the JOBO rotary processors was going to increase the contrast on any films processed in them. We began exhaustive testing in search of the elusive magic factor which would allow us to say "To process BW films, simply multiply your developing time by X, and your rotary processing will work perfectly."

When we found a factor on one film that worked well for a single developer, we then tried that film in other developers. We quickly discovered that the factor did not translate to many of the other developers. So we reversed our approach and tried different films in the same developer. Again, we quickly discovered that one factor would not work on many different films in the same developer.

Then after a year or two of frustration, one of the technical staff at JOBO Germany told us to try a five minute presoak in water. So we tested a wide variety of films and developers and the vast majority worked well simply following the normal hand-inversion instructions from the developer manufacturer, and preceding it with this five minute presoak. While some of the combinations of films and developers needed minor adjusting, nearly all the tested materials came within 5% of being right on target for delivering excellent results. We also tested shorter presoak times and found they did not work well at all.

So JOBO USA began recommending five minute presoaks for all BW developer and film combinations. Then about 1988 Kodak came out with T-Max films, and for the first time in our memory, a film manufacturer had included rotary developing instructions. Basically they had followed the same instructions we had discovered, and there was no need for any changes.

Then about three or four years ago, Kodak introduced Xtol developer. This time they not only had rotary processing instructions, they also had a whole instruction sheet dedicated just to rotary processing and for the first time in recent Kodak history, they gave instructions for other brands of film, as well as their own. But most importantly for JOBO, they indicated that all their developing times were for use without presoak. THIS is what caused all the discussion on the internet newsgroups. Why should Kodak advocate no presoak when JOBO advocates a presoak?

Go back to the history of the story, and the answer is clear. JOBO was looking for a SIMPLE way to get customers successful in their processing. The presoak provided that simple "common denominator" that enabled us to tell customers, "Presoak for five minutes then process normally."

What Kodak did was an enormous amount of testing, and published the results. Neither method is right or wrong. They both work well. If you are currently presoaking your film and getting the results you like, then keep on doing it. If you are starting without a presoak and you like the results, then keep on doing it. As I’ve said before, photography is not a pure science- it’s really alchemy. Enjoy it.

Note: JOBO does not ordinarily recommend a presoak for color films since it may cause a slight color shift.

 

[Don Wallace]

Don, you might be experiencing developer exhaustion. With HC-110 Kodak says you need 6mL of syrup (US bottle) for each roll of 35mm or 120 or each sheet of 8x10 film. Extrapolate down and you'd need at least 3mL of syrup for 2 sheets and 4.5 for your 3 sheets.

So I'm curious as to what tank you're using to develop these sheets and how much syrup/water you're using.

Jeremy, I am using 3-4 ml syrup per sheet so I don't think that is the problem. Also, I am pretty sure that Kodak recommends 12.5 ml per sheet of 8x10. At least that is what I get when I do the math from their tech sheet on 8x10.

I use the same ratio of developer in my Expert Drum for 8x10 and 5x7 and don't have the same problems with inconsistent density in skies, etc. There is something about the rotary processor, I think, that is doing this.

 

[Photo Engineer]

My latest Jobo instructions and the data from the "Rotary Processing Journal" published for years by Jobo state that the higher rotatoin rate is best in all conditions and that a prewet is best in all conditions.

I used it for nearly 5 years with slow and finally, for over 15 years, with the fast rate and find that the latter is far superior with film wrt uniformity. I have both a CPE and a CPP and a variety of 1000, 2000 and 3000 series drums.

I do not adjust development times, and do both color and B&W.

PE

 

[Jim Chinn]

I do not adjust development times, and do both color and B&W.

I always wondered about the JOBO recommendation to decrease development times. Every film I have shot I have used the same times as for hand agitation and found no difference in the negs regardless of formats. Perhaps if one is using a developer dillution requiring very short times it might make a difference.

 

[Photo Engineer]

Jim;

You are most likely right. I use longer development times except for C-41, but that is a "special" case.

PE

 

[Don Wallace]

OK, I finally shot 4 sheets of FP4 with lots of blue sky. Those of you living in Ontario this summer will understand why it took me so long to find some blue sky outside of normal working hours.

I just checked the normal times for FP4 in HC-110 B and Ilford says 9 minutes if rated at EI 125. I have been rating it at 100 so that is close enough for a test for inconsistent skies.

Ilford also states that one should reduce the time by 15% in a rotary processor without a pre-rinse, but then adds that they do not recommend a pre-rinse since it leads to uneven development. I am now wondering if my inconsistent and blotchy skies are because I started using a pre-rinse.

Well, what the hell, I will try both. It is pouring rain again (gee, that's a surprise) so I am about to descend into the Room of Darkness. Test 1 will be:

- all at fast speed, 68F/20C

5 minute pre-soak
9 minute development in HC-110 B
wash for 1 minute
fix for 2 minutes
wash for 1 minute
HCA for 2 minutes
wash for 5 minutes

One final question: I use the 2523 tank, the one that holds 6 sheets of 4x5 on a spiral reel. Should the emulsion face in or out?

 

[grahamp]

I put the emulsion in. Mostly so that the backing is on the outside in the theory that it is a) more robust b) that's how it seems most natural removing sheets from the holders.

 

[Ole]

I use the slow speed for Bw and high speed for E6. No problems yet...

 

[Don Wallace]

Ole, what are your shortest development times. Do you use a presoak?