Combiplan vs. JOBO Expert Drum 3010

Up until recently, I had been using a CombiPlan plastic film holder for 6 4x5" films and developing using a multi-tank array. I agitated by raising and lowering the film holder in the developer 3 times every 30 seconds. I had tested my film development more or less according to BTZS using a Stouffer step wedge and measuring the gradient at different developing times. Even though the Stouffer wedge has two fields with identical density, the results on my test negatives were always somewhat off (0.02 to 0.04 as measured on my Heiland densitometer). My curves were also somewhat uneven. I attributed this to measurement error, although I checked the densities on the Stouffer wedge several times and always got identical results.

I got tired of developing in the dark and wanted to try the JOBO rotation system, which of course also uses less chemicals (my tank array required 1200ml to cover the film holder fully). So I splurged and bought a brand new JOBO CPP-2 with lift and a JOBO 3010 Expert Drum.

I did a test run this weekend to check development times with the #4 speed rotation as recommended by JOBO for this drum. To my surprise, I got very smooth curves (see attachment) and the results for the duplicate density field were identical on all my test negatives.

Looking back at some of the images I developed over the last few months, I realize that I often have visible effects which I attributed to uneven lighting due to clouds that I had not noticed when taking the picture. So now I realize that these effects and the uneven density results were due to uneven development using the CombiPlan holders. I am happy to have found that I can improve the quality of my negatives with the new system, but am also very unhappy knowing that there was uneven development with the nearly 400 4x5 sheets I have developed since I got the CombiPlan system (I used to use tray development).

Now I need to set my new standard developer for the JOBO developing system for my normal film (FP4+). XTOL 1:1 gave me too short times with FP4+ using rotation. I aim for a gamma of 0.57 for normal development and like to have room for at least N+2 and N-1, but I am at nearly normal development with only 5 minutes. So I will either try more dilute XTOL (1:3) or another developer. I have read that at least 25ml of XTOL stock should be used per 4x5 film, so with 10 films I would need 250ml + 750ml water which is the maximum volume rated for the 3010 drum (minimum only 210ml). Or maybe I will try another developer, anyone have suggestions for rotation processing FP4? I like to have developing times of around 10-12 minutes for normal contrast so I have plenty of room on both sides.

So for anyone else considering the CombiPlan system - I would recommend don't!

The Combi-Plan was designed to be used as an inversion tank, just like you do with 35mm film in the round stainless steel tanks. This gives more vigorous agitation than your raising and lowering the film hanger in the tank. I have processed small runs of all types of film in combi-plan tanks, and have always achieved excellent results, b/w, C-41, and E-6. I always treat the tank as an inversion tank, though.

I tried inversion but had problems with leaking and the lid is very hard to get on and off. So I switched to the tank array which is actually made by Nova, it consists of 5 tanks in a heated waterbath. But this requires everything to be done in the dark and of course is not designed for inversion, and obviously dunking is not enough.
Hal

Maybe now you will do as I did several years ago and destroy that CombiPlan so it can't ruin another workers negatives.

I run my Expert drums even slower than "4" and haveno problem with streaks, etc.

Well, I don't know. If the Jobo is working well for you and you like it, then by all means use it. I'd probably do the same myself if the budget allowed for it. I have the CombiPlan tank, and use it the way it was intended - as an inversion tank. Once you develop the knack for loading it properly, it does a fine job and doesn't leak too much. Maybe the previous poster didn't tighten down the funnel enough. You loosen it to allow air to escape while pouring chemicals in and out. Tighten it down before you start inverting.

Best of luck with the Jobo. I think you'll find that dilute XTOL will provide the elongated processing times you need.

I have two combi-plan tanks and have no problems with either.
One must be careful with the tightening however, as I've found out.
On the other hand, I'd sure like a JOBO system too.

Jim Noel said:

I run my Expert drums even slower than "4" and haveno problem with streaks, etc.

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Hi Jim, what speed do you use with your Expert drum? I have only tried JOBO's recommendation (P for roll films and 4 for expert drums).
Thanks,
Hal

hal9000 said:

Up until recently, I had been using a CombiPlan plastic film holder for 6 4x5" films.....

Click to expand...

I never got good results with the Combi using the full load of 6 sheets, and started processing 4 at a time, (with the gap between the sheets on each side) and this seemed to solve the problems. But a high level of agitation might also be an issue - I think maybe the way the film is held in curved channels tends to introduce undesirable flow characteristics and backing off on agitation should minimise this.

I also use the Combi for inversion, and once I had got te hang of it, and used it exactly as per the instructions, I have had good results with it. Looking at those curves, there is a hump in all around around density 1.6. This looks too regular, and if it was a fault due to agitation, I would have expected a more random result. If you flattened out the "bumps", then the curves look reasonable.

One other point, the developer dilutions are not identical, so a direct comparison is perhaps not valid. I know it is probably not possible due to the amount of chemistry that can be used, but 1000ml of 1+3 will give different results to 500ml of 1+1.

Steve

I bought one combi-plan tank, thinking of making the array for a little dip-n-dunk line in my sink if I liked it. Mine leaked from the drain plug, no matter how tight you dialed the drain stopper. After using it a few times, the lid to the tank had warped sufficiently that it could not fit on the tank properly no matter how hard you twisted and jammed. I went to the Jobo Expert drums, and have NEVER looked back. I run my Jobo CPA2 at the slowest possible setting, just above the OFF position for the motor, and I get perfectly even negatives, which print beautifully on platinum/palladium. Five Combi-Plan tanks? That's almost two Expert drums in cost! Yikes!

keffs said:

Looking at those curves, there is a hump in all around around density 1.6. This looks too regular, and if it was a fault due to agitation, I would have expected a more random result. If you flattened out the "bumps", then the curves look reasonable.

One other point, the developer dilutions are not identical, so a direct comparison is perhaps not valid. I know it is probably not possible due to the amount of chemistry that can be used, but 1000ml of 1+3 will give different results to 500ml of 1+1.

Steve

Click to expand...

Actually, the regularity in the bumps seems to be due to the fact that the densities go up at the wedge steps that are on the edges of the test negative, so the edges get more agitation than the central portions of the neg. Which also can be seen on prints (I have attached an example, the facade was evenly lit on a more or less cloudless day but the unevenness is obvious in the print). As far as the dilutions, I had done a number of tests at various dilutions with the CombiPlan and all curves have more or less similar bumpiness, I just chose the 1+3 as a comparison.
Hal

If your CPP-2 is brand new, it has the latest rotation motor. In that case, you should be using rotation speed "F" with Expert drums, which is around 46 rpm. The documentation telling you to use "4" is out of date and incorrect.

Slowing from "4" to "F" might extend your gamma 0.57 time somewhat, but not from 5 minutes to 10-12 minutes in my experience. If that new time is long enough to make you comfortable with whatever "minus" times associate with it, great. If not, there's no reason not to use Xtol 1:3 as long as it's very fresh.

My preference for developing FP4 Plus in a CPA/P-2 and Expert drum at rotation speed "F" is Perceptol 1:1. My times (here in warm southern California) for that combination, to achieve a gamma of 0.51, with a 5-minute pre-rinse, are 8 minutes 30 seconds at 75 degrees F or 5 minutes 50 seconds at 81 degrees F.

Sal Santamaura said:

If your CPP-2 is brand new, it has the latest rotation motor. In that case, you should be using rotation speed "F" with Expert drums, which is around 46 rpm. The documentation telling you to use "4" is out of date and incorrect.

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Hi Sal,

Thanks for the tip. My CPP-2 is in fact brand new, but the instruction manual that came with it suggests speed 'P' for the 1500, 2500 and 2800 series drums and '4' for 3000/Expert. The serial number of my unit is 24663. Do you have a link to a more up-to-date guide? Where did you get this info from?

My preference for developing FP4 Plus in a CPA/P-2 and Expert drum at rotation speed "F" is Perceptol 1:1. My times (here in warm southern California) for that combination, to achieve a gamma of 0.51, with a 5-minute pre-rinse, are 8 minutes 30 seconds at 75 degrees F or 5 minutes 50 seconds at 81 degrees F.

Click to expand...

Thanks for this tip as well, what IE do you shoot at for FP4 with Perceptol 1:1? I have been using IE 80 for FP4 with XTOL 1:1.
Regards from Berlin,
Hal

hal9000 said:

...the instruction manual...suggests speed...'4' for 3000/Expert. The serial number of my unit is 24663. Do you have a link to a more up-to-date guide?

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The late, lamented Jobo USA had a comprehensive Web site as well as a staff that kept it up to date and very informative. Fortunately, Omega-Satter, the current Jobo distributor here, rehosted that Web site. Here's the page you need:

Dead Link Removed

All the phone and email contacts at the bottom are obsolete (except "Webmaster") but the technical information is good.

hal9000 said:

...what IE do you shoot at for FP4 with Perceptol 1:1?...

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With exposure determined by a Zone-VI-modified Pentax digital spot meter and the negatives read by a calibrated densitometer, my FP4 Plus EI, when developed as described above, is 160. Note that I wouldn't process more than 8 4x5 sheets in 1 liter of Perceptol 1:1. Compared to Xtol 1:3, that would decrease your capability by 2 sheets per run. I'm not sure how the negatives' grain would differ from those processed in Xtol 1:3, since I've not tried that combination. Happy experimenting, Hal!

<Now I need to set my new standard developer for the JOBO developing system for my normal film (FP4+). XTOL 1:1 gave me too short times with FP4+ using rotation. I aim for a gamma of 0.57 for normal development and like to have room for at least N+2 and N-1, but I am at nearly normal development with only 5 minutes. So I will either try more dilute XTOL (1:3) or another developer. I have read that at least 25ml of XTOL stock should be used per 4x5 film, so with 10 films I would need 250ml + 750ml water which is the maximum volume rated for the 3010 drum (minimum only 210ml). Or maybe I will try another developer, anyone have suggestions for rotation processing FP4? I like to have developing times of around 10-12 minutes for normal contrast so I have plenty of room on both sides.>



Guten tag aus Florida!

I agree about the Jobo. A very simple method to get your film curves is to consider using the services of Fred Newman at Beyond The Zone System. Fred can easily do film tests for you, and will plot the results and send you the graphs so that you will have your own individual film speed, and the correct developing time for whatever subject brightness range your meter reading reveals. Please see the web site, or feel free to send me a private message so that I can give you additional information. Best of luck.

Edwin Mahler

Mahler_one said:

A very simple method to get your film curves is to consider using the services of Fred Newman at Beyond The Zone System. Fred can easily do film tests for you, and will plot the results and send you the graphs so that you will have your own individual film speed, and the correct developing time for whatever subject brightness range your meter reading reveals.

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Thanks, I am sure that's a great service for a lot of people but I actually LIKE to test film and would also feel better knowing that it is tested with my development conditions.
Regards,
Hal

XTOL 1:3

I just wanted to let anyone know who might be interested - my tests with XTOL 1:3 were very good, I have good development time for normal contrast (10 min) and lots of room for expansion and contraction from N+3 to N-3. Here are my development times using 50rpm in the CPP-2 at 20°C:

N+3 (gamma 1.000: 27 min
N+2 (gamma 0.800): 19.5 min
N+1 (gamma 0.667): 14 min
N (gamma 0.571): 10 min
N-1 (gamma 0.500): 7.5 min
N-2 (gamma 0.444): 5.5 min
N-3 (gamma 0.400): 3.5 min

hal9000 said:

Hi Jim, what speed do you use with your Expert drum? I have only tried JOBO's recommendation (P for roll films and 4 for expert drums).
Thanks,
Hal

Click to expand...

I turn on the power switch until it clicks on, and no further. This is the slowest possible rotation. I began doing this when I awitched to pyrocat hd and have never had streaks.