Manual developing with Jobo 2500

[Luca Merlo]

I have been experiencing major problems developing 4x5 films with a Jobo 2500 tank and manual rotation. The tank leaks heavily (I own three of them and they have all the same problem). On top of that I find the rotation really awkward. I have therefore decided to agitate the tank by inversion. The process is OK but the negatives were heavily underdeveloped. I am now wandering if by prolonging the development time I will be able to get proper results or the lack of head space is not allowing a proper agitation of the developer and therefore the negatives can only get a "physical" (superficial) development.

[Nick_3536]

The 2500 is a line of tanks. Which tank do you have? The only time I've seen 2500 tanks leak is if the lid isn't seated right or if it's a multi-section tank if the section isn't seated. Are you sure you've put the lid on straight? What volume of chemicals are you using? The smallest tank won't have much head room.

[Luca Merlo]

I have the smallest tank. The one that can accomodate only one 4x5 reel. When agitating by rotation I use 600 cc of developer and this is giving me good results. When agitating by inversion I use roughly 1,450 cc of developer. Thsi is allowing the complete coverage of the negatives and allows some head-space for the recirculation of the developer.

[ronald moravec]

Done it may times woth yourset up without problems. 1400 uses almost all the head room.

Put the reel in the empty tank without the top and measure how much developer to cover the reel and then you will need to add perhaps 50/100 more as you can`t cover the reel without the top.

Store top off the tank so you don`t stretch it. Also you will need the lid that takes the 3" dia cap for the lid for inversion. You do not use the cog lid for machine agitation. There is also a center filler down the middle of the reel required for light trap and proper filling.

[Henry Ambrose]

You need to use the larger tank that holds two reels. This will hold enough solution to cover the film and have enough space left over for agitation.

The small tank -barely- holds enough solution to cover the reel. Put a reel in the tank with the top off and fill it with water. Look at what space you have when its filled to the top - that's not what you want at all.

As for your leaks, I don't know - the Jobo tanks I have do not leak. Are you sure they are assembled correctly?

[Luca Merlo]

Thank you very much to all of you. I think that having 3 tanks I will follow what roland is proposing and, if it does not work, I will follow Ambrose. The leaking is a real problem and it is the same situation I have experienced for many years with the old Paterson tanks (the ones with the gasket and the grey lid). Due to their design, they were leaking. Here I face a similar problem. By rolling the tank on a table the lid tends to come apart and the tanks start to leak (not a lot but several drops).

[Sanders McNew]

I've used the 2500-series tanks to process 4x5 sheets for years now. I will shoot 24 sheets of TXP in a session and process them in two tanks.

They are not made for inversion. They want to be rotated. I understand you do not want to roll them on a countertop. Why not just buy a used Beseler or Chromega roller base for one of their tanks? They are easy to find, cost maybe $25 apiece and work fine with the 2500-series JOBO tanks. And they work well also with the 3000 JOBO expert tanks.

It is much more convenient than inversion agitation. Fill the tank, set the timer and go do something else while the tank rolls around and around on the base. Try it.

Sanders McNew

www.mcnew.net

[paulr]

i'm curious to know if you've ever been able to get even development, without streaks, using these tanks this way.

[Luca Merlo]

Sanders, thank you for your suggestion. I am an Italian photographer and here LF cameras, lenses and ancillary equipment almost disappeared several years ago..... we have so to rely on the American sources but when it comes to purchase electric equipment you have to uderstand that we have to alter the motors to adapt them to the European electical frequency. I have been developing B&W roll films for the last 30 years using Paterson tanks and inverting them. Once you are accostomed to a method you simply try to stay this way ...... the cost of the developing agent is not an issue since I use only Rodinal that is very inexpensive in the old Europe. By the way, this morning I realised that Jobo sells a module (N. 2560) that, attached to the tanks I own (2521) increase the capacity of the tank and in such a way one can accomodate 2 reels for 4x5 leaving a lot of space for the agitation of the chemicals. This should solve my problem. I will try and I keep you posted. Paulr, thank you for the message. Franckly I do not think that developing the sheet films by inversion you could have problems of even development or streaks. I will keep you posted anyway.

Thanks again and ciao to all of you

Luca

[paulr]

"Franckly I do not think that developing the sheet films by inversion you could have problems of even development or streaks. I will keep you posted anyway."

I asked you this because a while ago I asked a Jobo technician about agitation by inverting the tanks. I was looking for a way to use the jobo tanks without a processing machine. He warned me that I was in for trouble trying to use them as inversion tanks ... they are designed to provide a smooth flow of chemicals over the film in a rotating tank, not one that's being inverted on the other axis (which is how patterson tanks are designed).

The solution he suggested is a motor base, which has worked well for me. I never bothered testing what he said about hand-inverting, so I was wondering if you had.