Developing in Jobo 2850

[Sloaah]

I am a newcomer to LF photography, having recently purchased a 4x5" camera, and am now looking towards developing solutions.

As it stands, I have ordered a Jobo 2850 (2830 + 2870) for my prints, which should arrive within the next week or so. My understanding, however, is that 4x5" prints are not possible in this setup, suggesting that the same applies to 4x5" negatives (I have done a lot of reading on this subject in LFP's forums, and it seems that many people develop their 8x10s in 2800 series tanks, so I would assume theoretically 4x5" is also possible).

Is it possible to use the 2850 for 4x5? I can get some reels if necessary, although I don't know whether the 2509n would fit. Otherwise I am thinking about a Paterson orbital since I can't find 2500 series tanks on ebay...

Thank you in advance for your help.

Anatole

[natelfo]

The Jobo 2830 is the same thing as the 2551, which is a tank designed to hold 2 4x5 reels. The only difference that I can see is the printing on the side (I'm comparing my 2820 to 2521 and pics of the 2830 to my 2551. The 2830 may or may not have a magnetic base, but otherwise they should be the same. You can get a center core and 2509n reels to use in this setup, just make sure the lid (either capped or open cog), does not have the "fluid cup" inside. This is a cup that limits the amount of liquid that can be dumped in at each phase. The tank should come with little round clips that snap onto the ribs inside the tank. These are meant to hold individual sheets, the 2830 would hold 4, with the 2870, you should be able to hold 8 individual sheets, or four 4x5 reels. I have read about people having film pop out when processing when clipping the film directly to the tank, but I have never used mine this way.

[natelfo]

Also, the center cores interlock with each other, acting as their own extensions. Just make sure that if you use the extension tube (2870), you have enough core pieces to reach from end to end (one core piece for each reel), otherwise you could ruin your film as the core acts as a light barrier when the lid is open. You would need 4 of the single core pieces for the total setup, or just 2 if you are only using the 2830. I don't know if they made any double or quadruple length cores.

[natelfo]

Sorry, I must be smoking crack, I just looked at mine. The cores are extendable, but the base core piece is not the same as the extension pieces. The base piece has a flange at the bottom, the extensions do not.

[tgtaylor]

I have the 2850 which I have attached to the 2820 test drum. The 2850 by itself will hold 2 2509N Reels = 12 sheets of 4x5 and requires two core extensions connected to the one with the flange. However the regular top extension, which is approximately 1/2 the length of the regular extensions, is designed to fit into the last extension and does not have the two slots for interlocking with another extension. That said, the 2850 with the 2820 combined will hold 3 2509 reels and the center core protrudes above the tanks rim and the lid locks down firmly on the tank. No movement from inside can be detected by shaking the tank.

In any case the 2800 series of tank can be used to process film with 2500 series reels - including the 2809 series - provided you have the requisite center cores. I have several 2500 series tanks for processing film and use the 2800 series for paper. I have never processes film in the latter.

Thomas

PS: I also have the 2830 which is not a module (it has a closed base) and it will hold 2 2509 reels.

[al olson]

. . .
My understanding, however, is that 4x5" prints are not possible in this setup, suggesting that the same applies to 4x5" negatives (I have done a lot of reading on this subject in LFP's forums, and it seems that many people develop their 8x10s in 2800 series tanks, so I would assume theoretically 4x5" is also possible).

Is it possible to use the 2850 for 4x5? I can get some reels if necessary, although I don't know whether the 2509n would fit. Otherwise I am thinking about a Paterson orbital since I can't find 2500 series tanks on ebay...
. . .


The 2500 series and the 2800 series are the same diameter tubes and you can mix and match all of the tubes and caps between them. Their system for designating the different tubes is confusing because the same tubes (length & configuration) may have different numbers.

I believe that the differences are the markings on the side that tell you how much liquid to use vs. number of sheets. The 2500 series has markings for films and the 2800 series has markings for paper. I also have several tubes that have no markings at all. In addition, Jobo made it more confusing because the 2850 refers to both tubes in a two tube set, whereas the bottom tube may also be a 2560 or a 2840 or a blank tube.

The 2509N reel fits all of these tubes and I usually develop 4 to 6 sheets at a time using a single reel and either the 2820 or 2521 tube.

A tube such as the 2560 or any of other the long, closed-on-one-end tubes can also be used to develop 2 sheets of 8x10. Just fit the sheet between the high raised ribs. By adding the extender tube you could do 4 sheets.

I do this without any problem, but some people have complained about getting streaks where the negative touches the ribs. It is necessary then to put it back into a fixing bath, or sometimes just a water bath will do, to remove the dye on the backing.

[Mkillmer]

The other option is to use he cup lid. You will not need the center cores, but the cup will take up space. You might be able to fit 2 4x5 reels in a 2850 with the cup- certainly one is no problem. You will use more developer, but if you reuse, or use a dilute developer (eg rodinal) this doesn't really make a difference.

[koh303]

I am a newcomer to LF photography, having recently purchased a 4x5" camera, and am now looking towards developing solutions.

As it stands, I have ordered a Jobo 2850 (2830 + 2870) for my prints, which should arrive within the next week or so. My understanding, however, is that 4x5" prints are not possible in this setup, suggesting that the same applies to 4x5" negatives (I have done a lot of reading on this subject in LFP's forums, and it seems that many people develop their 8x10s in 2800 series tanks, so I would assume theoretically 4x5" is also possible).

Is it possible to use the 2850 for 4x5? I can get some reels if necessary, although I don't know whether the 2509n would fit. Otherwise I am thinking about a Paterson orbital since I can't find 2500 series tanks on ebay...

Thank you in advance for your help.

Anatole

In order to use your 2850 for 4X5 sheet film processing you will need to convert your 2830 (bottom section of the 2850) to use with film. This will mean getting (or swapping) these parts out:

1. In the lid - Replace the beaker light (#03049) trap with a funnel light trap (#03042)
2. Get a center core. The 2830 is the same tank as the 2560 (multitank 6) and for that you would need the following core combo - 04044+04045+04073.
3. Get some 2509 reels.

The 2830/multitank 6 will take up to 12 sheets of 4X5 (with room for one reel of 35mm).
You can find all the min filling quantities here:
http://www.jobo.com/jobo_service_analog/us_analog/instructions/instructions_misc_tank_and_drum_capacities.htm

Good luck!