View Full Version : Jobo Expert Drum and uneven processing.

1-May-2006, 10:30
I am using Jobo Expert Drum for 4x5 processing. Often I have the problem with uneven processing. There are areas on the bottom part of the negative, usually right next to the edge, which seems to receieve no chemistry. Strikingly, sometimes they clearly received developer but did not get the fixer. I always load the film dry, then prewet for two minutes and proceed to processing. I use the drum on unicolor roller. I will appreciate any advice to solve this pretty frustrating issue.


Oren Grad
1-May-2006, 10:36
Is the drum leveled when you're using it on the roller, so that solution flows to the end of each compartment?

1-May-2006, 10:41
Yes, the drum is leveled. I wonder if it has to do with "stright" loading of the film. I never payed attention to that but just saw that Jobo reccomneds the film edge ideally parallel to the edge of the compartment. Could this cause a problem?

Dan Jolicoeur
1-May-2006, 10:43
Are you using the unicolor roller that reverses after about 3/4 of a turn with that drum?
If so I would remove the mechanical reversing switch and let it run in one direction and it will be fine. I use the 2509 reel with a 2500 series drum on a homemade roller that works fine.
2nd, Howmuch volume of chemistry are you using?

Eric Biggerstaff
1-May-2006, 10:55
What drum are you using?

I use the 3010 on a Beseler motor base with no problems. Although Ilford and Kodak don't recommend a presoak, I do one as well and have no issues with uneven development. With the 3010 drum it is pretty difficult to not load the film straight, and having used the 3006 several times I never had a problem when loading the film.

Are you using enough chemistry?

Recently I noticed some problems with my negatives with a straight line of what appeared to be under developed areas. At first I thought it was the processing but it turned out to be a fogged area of film from pin holes in my bellows. So, perhaps it is not the development process but an issue with the camera or even film holders.

Just a thought.

Good luck!

1-May-2006, 10:58
I have already removed reversing swich so it rotates in one direction only. The volume of the developer is always 300-350ml. I use more of the fixer, usually 500 ml. But I think the volume is not where the problem is as sometimes I see these araes developed but not fixed. This seems wired to me because if the drum was not correctly leveled or there was an air bubble trapped somehow, or there was not enough chemistry volume I would never see these areas developed, I guess. Maybe the film moves somehow inside the drum while I pour the developer out, but it does not sound likely to me.

1-May-2006, 11:04
This is 3010 drum. I do not think the problem is related to the camera or film holder. I can clearly see the area which was not developed or not fixed. This is not just darker area, it is unprocessed emulsion. Sometimes there is an stright line on the bottom edge of the film which looks like this, more often there is irregular "spot" right next to the bottom edge. Sometimes it is really bad - 3 out of 6 negatives can be affected.

Eric Biggerstaff
1-May-2006, 11:20
Is there any way you can post an example of a problem negative?

Are you using two sheets per tube or only one? ( I always try and use two, in fact I will keep old, dated film as "filler" to make sure there are two sheets per tube)

If you do both single and double at times, does the problem occur when using the two sheets per tube versus the single sheet per tube?

Or does it occur no matter how many sheets are in each tube?

Have you checked each tube to make sure there is nothing broken that might be allowing one film to touch the other while processing?

Have you tried to increase the amount of developer to 500ml as opposed to 350ml? I tend to use more than what Jobo recommends.

This is a difficult one, I seem to feel it is either a mechanical breakdown somewhere along the way or not enough developer in the 3010.


ronald moravec
1-May-2006, 11:43
The sheets are maybe overlaping.

I always load rights leaving 1/2 in sticking up, then the lefts. Then push them both down.

Feel both ridges that are supposed to separate the sheets. If you can`t feel it or the sheets do not go down straight between the ridges, they will overlap.

Before you start removing the film next time, shine a light down to see how they are loaded so you can acesses if this is the problem.

Joseph O'Neil
1-May-2006, 11:50
I use a similar setup as you do, but the 2500 series drum However, some "rules' apply to all drums, so . if you want to try, a couple things I would try changing:

1) most problematic, as I see it, is constant rotation all the itme in one direction. I would physically pick up the drum once *every* minute and rotate it so it is going "backwards" compared to the direction it was just going.

2) Use more developing solution, regardless of type of developer used, in any Jobo drum than Jobo calls for. As a rough rule, increase by 20% , and experiment form there.

3) how fresh is your fixer? Personally I am a great beleiver in one shot developing. One shot developer,a nd I only reuse my fixer the actual day I am processing. Weakening your solutions down, nd increasing your development times correspondingly is not only economical, but IMO, allows you more control over your development. Anyhow, very easy to exhaust or cross contaminate fixer and other chemistry when not using one shot developing, so check over your steps one by one.

4) Increase your presoak time. I use 4 to 5 minutes in my 2500 drum. Your milage may vary (YMMV).

...and one last total shot in the dark..what kind of developer are you using? Some powdered developers cam giv eyou odd results if not mixed properly. Liquid ones too I suppose, but I see it more with powdered developers.

good luck


1-May-2006, 12:13
1)I always load only one film per tube. Actually, I did not know I can load two, Jobo booklet I received with the drum calls for only six films per drum. The problem seems just random - sometimes all negatives are just fine, sometimes one is affected, sometimes more of them. Yesterday I had 3 out of 6 loaded affected and this really made me crazy as I liked the photos very much.

2) I inspected the drum and can see no difference between the tubes - they all seem just fine.

3) Of course I can post a scan of an affected negative. I do not have my negatives with me, I will post it latter today.

4) I do not think the problem has to do with exhausted chemistry. I use one shot developers, PyrocatHD or WD2D+ diluted from liquid stocks I buy. I do reuse fixer but when I use the same batch of the fixer with roll film it workes just fine.

5) changing the rotation direction, using more of the developer sounds very resonable to me, more then 500 ml is probably not possible as the drum becames to heavy for the motor base, I will also extend the presoak time.

Eric Biggerstaff
1-May-2006, 12:32

If the drum is indeed a 3010 it will handle 10 sheets, this should be indicated on the drum itself. If the instructions you got with the drum indicated it will only handle 6 sheets then you probably have a 3006 or you got the wrong instructions with the drum.

I do not change directions with my drum on the Beseler base and have no problems, but this is a good idea for sure. You can also try to eliminate the presoak and see what happens, as I said, Ilford does not recommend this step as it can lead to uneven development.

I am not a Pyro person, but for some reason I seem to recall that Pyrocat HD and WD2D+ were not recommended for rotary development in drums, I am sure one of the many Pyro users will correct me on this.

Try the 500ml of developer as opposed to 350ml, this might help. Also, you might want to try some testing with other developers like DDX , Xtol, etc. and see if you still have the issues.

Before you go out and take some images that matter, make a buch of test negatives around your house and develop them trying some of the suggestions you get. It is better to burn through several sheets of film testing then getting disappointed when you return from an outing with problems occuring on images you care about. Film is cheap by comparison.

These situations are frustrating for sure which is why testing is so important. Not a fun thing to do, but pays off in the long run.

Scott Davis
1-May-2006, 12:49
Eric- Pyrocat HD was specifically formulated for the express purpose of using a Pyro developer in rotary processing. PMK generally does not do well, unless used in excessive volumes. The other Pyro developers like ABC and 510 Pyro oxidize like the PMK does, which make them unsuited for rotary processing. I don't know offhand about WD2D+, as I've never used it. I would NOT eliminate the presoak - it does two things:

1. It helps get the film to temperature so it is not shocked by the developer (this is more an issue in places which have climate extremes, particularly with cold weather).
2. It removes the anti-halation coating, which although it may well be inert, still adds something else to the chemistry that may negatively influence developer performance.

Michael Alpert
1-May-2006, 13:13

I have a simple suggestion that I am making without irony: Follow Jobo's Instructions. If you have somehow altered the machine, change it back to the way it was when new. Use your chemistry exactly as directly, and, for goodness sake, put the film in properly. Only then will you know what is what. Jobo processors are in some ways very finicky and not well engineered or constructed, but they work reliably when they are used with care.

Eric Biggerstaff
1-May-2006, 13:15

Thanks for the correction. I might even give the Pyrocat HD a try!

1-May-2006, 13:26
Eric, thank you for correcting me - of course it is 3006. I did not remember the number, looked for a picture on the Internet and 3010 (closed) looks like 3006, that why I was wrong.

The problem with testing is that uneven processing does not occur always. Sometimes I get all negatives developed correctly and I can not figure the difference. Obviously I do something wrong, not always, but I just do not know what.

I think I do follow Jobo instructions. The only point where I did not was that Jobo recommends the edge of the film to be exactly parallel to the edge of the tube. I just did not remember of it. Could this be the reason? I do not know bu t will follow this.

BTW, Eric, I would really recommend WD2D+ instead of PyrocatHD, I was using Pyrocat (with FP4+) for some time because it has so rave reviews on the net but now I am back to WD2D+ which I love in the combination with FP4+ and Efke100.

Eric Biggerstaff
1-May-2006, 13:43

Thanks for the advice, I get so confused with the Pyro as there are so many different variations, one of these days I will try one. I did contact John Wimberley awhile ago and asked if I could use WD2D+ in a drum and he recommended against it, but I cannot recall why. As he developed the formula I never tried it, but maybe I will.

I hope you figure out what is going on with the development. Make sure to post a sample negative later as that may help us provide a better answer.

Take care and have a great one, we will figure this out! :-)

1-May-2006, 13:44
Jan I can't tell which motorbase you're using. Are you using a motorbase? If it's the Unicolor it can handle a LOT of weight. I tested it for 10 minutes with 2litres of developer in the big 2581 tank. The motor didn't even get warm. I think it was ten minutes. I routinely use 1+ litre. But I don't use expert drums.

tim atherton
1-May-2006, 13:53
And you really should presoak for 5 minutes not 2, that's not enough.

Finally, how are you loading the chemicals?

If you are taking the tank off, putting it upright and pouring them int he top, then you will have problems. The only way that really works is to use a funnel with a flexible hose, and fill while the drum is rotating - is that what you are doing?

(lastly, using jobo drums on a unicolor base, I found there were some developers that just didn't work with it (even though they work on the jobo processor) - giving uneven development etc. In part I think because of the particular speed and rotation cycle of the base. One thing I did find helped in some cases was actually to introduce a bit of random wobble into the tank - by putting a bit of "blue tack" (or whatever it' called in n.america) under the rubber of just one of the two roller wheels so there was a little bump. That introduced some random longitudinal flow within the tank

again - use more fluid. I've used up to 1l in a 3005 tank with 8x10 and my unicolor base coped fine

Jon Shiu
1-May-2006, 13:55
Hi, don't know anything about drums, but WD2D+ is not supposed to be used in drums due to rapid oxidation, ie you'd get underdeveloped negs unless you change out the developer.

1-May-2006, 14:20
Nick, this is a Unicolor motor base. When I receivied it I tried with different volumes and above 500-600 ml it just stopped. There here must something wrong with the base itself, I guess (do not thing it is directly related to the processing problem I have) - loosen belt, may be?

I will increase presoak time, of course sound like a good idea.

Tim, thank you for chemicals loading advice, of course I was doing it wrong. I will start using a funnel since now.

Jon, that is right, pyrogallol based developers are often not recommended to use with drums due to rapid oxidation. Pyrocat is pyrocatechin based. I use WD2D+ in a drum and get negatives I like very much, however. Of course when they do not get these owefull uneven processing.

tim atherton
1-May-2006, 14:32

you can get those funnels very cheaply at the big auto parts stores for using for oil changes - a plastic funel with a tube attached (some even have a type of twist flow control)

It's a bit of a juggling act you have to hold the funnel in one hand and guide the end into the tank fill hole, and then pour slowly with the other hand... not too fast or it overflows, but not too slowly either! (I'm glad I finally got a cheap Jobo CPA2...!) - but I did a few hundred sheets of 8x10 and 4x5 like this

Eric Biggerstaff
1-May-2006, 14:50

Tim might have an answer! Make sure the drum is rotating when you add the chemicals, I use a type of funnel similar to what Tim describes that I got from a local auto parts store. I am not sure where you are located but you can make one easily if you cannot buy a funnel as Tim describes. I have developed hundreds of sheets using my 3010 and Beseler motor base with no problems.

Good luck!

Patrik Roseen
1-May-2006, 14:57
"Curiosity killed the..." I'm interested in these 'rotating' proccessors as they are said to use very little chemicals compared to the Combi-Plan Tank I'm currently using (although the 'C-P T' is good for B&W it would be costly to developed chromes).

But what is all this about 'pre-soaking the negative'? I never do this - what good does it do to put alot of water into the gelatin...Doesn't that mean that the developer will be less efficient or that the different characteristics of the developer will be tampered with?

Please explain - as I'm eager to learn.

tim atherton
1-May-2006, 15:06
The short answer is that when they were working on the development times for continuous rotary processing, Jobo found that a 5 minutes presoak gave times that were basically the same as for the manufacturers recommendations for standard tray and tank development, so you didn't need a whole new compensated time structure. (apart from with xtol, where Kodak in its B&W swan song actually tested the developer in almost every combination conceivable, and actually came up for dev times without a pre-soak...)

People also find it aids with even development. As well, if the room you are developing in is quite a bit warmer or cooler than 20c (or whatever), it brings the film up (or down) to temperature before adding the developer and thus influemcing the developer temperature.

I'm sure there are other reasons too.

1-May-2006, 15:07
Eric, I will certainly try what Tim advices. I am located in Tucson, AZ, it is a town almost owned by car dealers so finding an auto parts store is not a big deal. I will also double check if my motor base is still well leveled.

Patrik, regarding pre-soaking I always do that, does not matter what kind of film (35mm, 120, 4x5) I develop. I must admit I just follow the instructions, did not do my own research. It is said that presoaking allows more even start of developing. Probably this is not a problem with 35 mm but more important with LF. But probably you will find here more experienced photographers which can explain better.

Oren Grad
1-May-2006, 15:59
The argument that a presoak allows a more even start of development is obsolete as a generalization; emulsions from the leading manufacturers have for many years now been designed to accept developer evenly from a dry start, assuming reasonable agitation. But while a presoak isn't mandatory, it is another one of the tricks that are available for us to try as we figure out all the voodoo needed to get good results working under the particular conditions of our respective darkrooms.

I develop sheet film in Expert drums on a Jobo CPA-2; I've never used a presoak and have always gotten excellent uniformity of development. (I don't use a presoak with roll films developed on reels in manual tanks either.) So Patrik, if your development ain't broke, there's no advantage to "fixing" it with a presoak; you might even create problems where none currently exist. But if you're having trouble getting even results, a presoak is a reasonable thing to try.

Paul Ewins
1-May-2006, 16:22
Drifting away from the original question a bit here;

I use a 3010 on a CPP-2. I don't pre-soak, but I always run the drum for five minutes before putting the developer in to make sure that the drum is up to temperature. I guess a pre-soak at working temperature would do the same thing and would be your only realistic choice for pre-heating the drum if running on a roller base.

I've never had a problem with uneven development, but then again I've only tried ID11/D76 and DD-X so far.

Oren Grad
1-May-2006, 16:43
I don't pre-soak, but I always run the drum for five minutes before putting the developer in to make sure that the drum is up to temperature.

I always pre-temper the drum as well. Through most of the year, the ambient temperature in my darkroom is lower than my process temperature. As Tim pointed out, if you're using the Expert drum on a manual roller without a tempering bath, that's another reason why a presoak may be useful.

Patrik Roseen
1-May-2006, 16:58
Sorry for 'hijacking' this thread...and thanks for the clarifications regarding pre-soaking...I learn something new everyday on this forum. I do not experience any problem (not pre-soaking) today. I develop in Aculux-2, 1:19, 20C for 15 minutes in a tank, with 5-10 sec agitation every minute. The JOBO-drum seems to bring advantages but also some difficulties ... reading some of the questions lately.

Oren Grad
1-May-2006, 17:20
The JOBO-drum seems to bring advantages but also some difficulties ...

Patrik, the Expert drums work beautifully when used as designed, as part of a system with the Jobo processors. Of course, the processors are expensive and not everyone can afford them. Using them in other ways, for example on a separate roller base or entirely manually, does pose challenges because you lose some of the features that are integral to the system, such as the tempering bath and the Jobo Lift that allows convenient introduction of chemicals while the drum is rotating.

But the nice thing is that, as many of the participants here have shown through their own experience, with a bit of patience and tinkering it's possible to resolve those problems and get excellent results from the Expert drums even under circumstances for which they weren't specifically intended.

Ed K.
1-May-2006, 20:12
Hi Jan,

I have a 3010 drum for 4x5, which holds 10 sheets instead of 6. I had what sounds like the exact same problem even after checking that all was level, making my fixer strong, presoaking and all of that. In fact, I ended up having two different problems. Naturally I can' t be positive that this is your problem, however I'll share it, and please pardon me if you know all about this:

First was that I had used an "archival" non-acid fixer in an acid process, with dilute stop bath to boot ( was out of rapidfix ) ( silly me!). Changing fixer to fresh rapid fixer got rid of the milky / foam part on the next run, but still negs were not even, not fixed well, and most of the dye remained on parts of the negatives. Then I boosted the fixer concentration to a level capable of preserving the dead - still no luck. I wondered how this could be, considering that the 8x10 expert drum worked so well from the first time.

Next, I tried the trusty old RTFM ( read the fancy manual ) approach. Low and behold, Jobo said NOT to push the negs in past the curved edge, and to just push them flush with the top of the tube. While I was skeptical about it, I did as the manual said, and - bingo! All great! Every time since ( hundreds of sheets ) has come out A-1, even and nice. Apparently, having the neg out from the curved radius of the drum's tubes causes it to flex and sort of pump chemicals behind and around the film.

Of course, still presoak, and all of that. I have heard that photoflo residue can cause problems too, so hopefully you have not run photoflo in your Jobo drum - if that's it, you'll need to clean it really well...

I don't know if the above still apply to a 3006 drum, but it's worth thinking about.

1-May-2006, 20:21
It seems likely that I follow your problems. I have read the manual and I must admit it just did not pay too much attention to how the negatve is loaded. I mean,if I push it too deep into the tube or nor, or it there is any radius between the film edge and the tube edge. It just did not seem to me very resonable - this was the tube filled with solvent so what could be wrong? I will try what you say.

I scanned my affected negative but I do not know how to post it to the forum - any idea?


Ed K.
1-May-2006, 20:41
Hi Jan,

If you can put your scanned neg on a web server or whatever someplace, then you can link to it in your posting as one way to do it. If you look under the link entitled "Formatting Help" when you make your post, you can see the suggested tags to use that make it show up.

Also, if you are not using a Jobo processor for your drum, the suggestions about filling it while moving and all that certainly apply, however pushing the film too far into the drum seems to be a sure-fire way to make uneven negs with an Expert drum for 4x5, at least on a 3010.

No need to fill the whole drum up. I suspect that the neg gets rocked / moved slightly as it enters the chemicals. The curved edge probably bends a bit and lets chemicals in when the radius is there to help.

I'm sorry that I either fixed or tossed my negs that came out bad, thus I can't post my mishaps. Some could be repaired simply by fixing them, however where I had used a wash aid, that seemed to make the damage permanent - so I tossed them.

Hope you find the solution - be sure to let us know how you did it!

Ed K.
1-May-2006, 20:48
In case you didn't get a manual, you can find them on the Jobo site.

Here's the part about loading the drum:

Jobo Site - Instructions for Loading Expert Drums ("http://www.jobo.com/jobo_service/us_analog/instructions/instructions_misc_expert_drums.htm#Loading%20the%20Drum" target=_blank)

1-May-2006, 20:54
Hi Ed,
thank you very much for your help - I posted the same question to APUG forum and I just uploaded the images there - http://www.apug.org/forums/showthread.php?p=296637. Does it resemble the problem you had?

I also included a picture showing how I do load the film, but i must admit this picture show rather how I think I load the film. As I said, I did not think it may have been important.


Ed K.
1-May-2006, 21:08

If you load your film as shown, it should work well enough. Emulsion to the inside, even with the top, although a tad more straight would be nice.

I had similar, and on some, much worse results. Sounds like you could test with some out of date film or non-critical stuff to find out. You'll know if it works or not in 20 minutes or less. It does look like you could have the same issue if the dark/opaque part is where the neg was not fixed properly. Did that dark part fail to clear properly, is it or was it milky looking?

1-May-2006, 22:10
this dark blob did not clear properly. It seems to me correctly developed but then not fixed, I would not call it milki. I am not really sure what you mean.


Ed K.
1-May-2006, 22:31
Yep, you got it. Not cleared properly. If it's only the clearing and not the development that's a problem, then filling technique is not the issue as much - if you got even development, but improper clearing with the correct chemistry, etc, and haven't put something on the back of the film to prevent chemical access to it, you've probably duplicated the problem I had with not loading the film correctly.

Again, good luck, and if you like, see photo on apug in reply to yours.

1-May-2006, 22:38
Ed, thank you so much for your help. I had a look at the pictures you sent to APUG - it is very likely that I loaded some of my films incorrectly. I have an impression I got where the problem was. I am going to do some tests soon and will post the results. I learned a lot here - loading technique, filling the drum. Thank you very much, gentelmen, for your input.

tim atherton
4-May-2006, 14:21
looking for something else I happened to come across the Jobo article on pre-soaking:

"To Soak or Not to Presoak

Recently, on the internet, we have seen questions regarding black and white (BW) rotary processing, particularly in regard to Kodakís 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 Iíve said before, photography is not a pure science- itís really alchemy. Enjoy it.

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

Ed K.
4-May-2006, 16:19
Good info Tim. I've tried what I would call "pre-rinse" vs. none. Pre-rinse meaning that I run tempered water for 5 minutes in the drum before starting the development. Both ways produce even development, however the presoak usually goes a long way toward dye removal and elmination of the dreaded "purple negs" syndrome. The developer removes dye, however if there is less of it to deal with, it goes away better by the time the full processing cycle is done. Unless I'm using a very mild developer, I get clear negs with no dye. I found no difference in evenness between pre-soaked Ilford and Efke sheet films whether presoaked or not when using a Jobo with expert drums. Ilford does mention a wetting agent in their recommendation not to presoak, right?

10-May-2006, 13:32
Since I got your advices I developed four times in Jobo drum and all of the films were fine. No uneven processing, no noncleared or non-fixed areas on the negatives. Here is what I changed:
1. I loaded the films very carefully, following the Jobo instructions (as Ed suggested). However, the films certainly moved during the processing.
2. I used more of the chmistry volume. Now I use 500 ml per drum regardless how many negatives I process.
3. I extended presoak time to 5 minutes.
4. I fill the drum using elastic funnel

I am not sure which of the above was crucial but it is all right now - once again - thank you very much.