Jobo 2509N 4x5 Reels and Uneven Development

[Colorado CJ]

I'm having troubles with uneven development when using the Jobo 2509n reels and a motorized base. What I am seeing is very uneven developing along the top and bottom edges of the negatives.

I've tried presoaking, using more developer, using less developer, etc... I've also used different developers, HC110 and Pyrocat MC. I haven't had any luck yet.

What I am resorting to is using 1400 ml of developer and doing inversion processing like a Patterson tank. I get good negatives this way, although sometimes I still get clear spots where the negative touches the triangle teeth at one end of the negative.

I'd like to work out a way to be able to use my motor base so I don't have to use so much developer and have a more automatic process.

Any help would be great!

EDIT: I am using a Bessler motor base that reverses rotation every 1 1/4 turn of the Jobo drum.

[tgtaylor]

I experience the same problem but only on the top of the negative when developing by inversion. This started about a year or so after I started using the 2509n reels which I bought new. I then switched to rotary processing with a CPA and the problem ended. I'm theorizing that it developed as a result of photoflo buildup on the reel which prevented an adequate flow in that area of the negative which rotary processing corrected by forcing the chemistry thru. I no longer put photoflo in the tank and instead fill a plastic file box that sidewalk chalk came in and treat 2 negatives at a time from the reel.

Thomas

[koh303]

1. You only need 1250ml if doing inversion (not that this matters much).
2. Are you using a new or used reel? A used reel might have wetting agent residue on the reel causing a delayed reaction in areas that are in contact with the film
3. Are you loading 6 sheet at a time, and are all sheets loaded correctly when you open the tank? A misloaded sheet which will have more pressure on either side.

[David Lobato]

I used to use the 2509 (not N) reels with great results a long time ago. When I started developing 4x5 again I got the 2509N reels with the black "wings". The wings are put on the reels after the film is loaded. I use 660 ml of working developer with XTOL only to get the 110ml of straight XTOL for every 4 sheets of 4x5 film. The drums says 560ml is enough working solution and I have used that much with D76 1:1 and HC110 dilutions. With the wings on the reels I have gotten good results. With my old reliable reversing Beseler motor base, I developed 12 sheets of Tri-X in XTOL 1:1 last week with no issues.

[ic-racer]

using more developer, using less developer, etc...

Underdevelopment in the center is a common symptom of developer exhaustion. Could be mistaken for "over development on the perimeter."

[vijaylff]

I had the same problem using 2509 reels on a unicolor base. Same reels on a Jobo CPP2 had no issues. So for me, it was a question of rotation speed. I don't need the temperature control of the CPP2 and I hate to use all that water but I haven't figured out another solution.

[Duolab123]

I have had good luck with the 2509 reels with the wings installed using the reversing Beseler base, The point about using enough XTOL is spot on, I have always used 1:1 with inversion but feel a little more comfortable using stock XTOL for 4x5 and 8x10 with the beseler reversing roller. Photo-flo is really kinda potent stuff, I think it's a silicone surfactant, I rinse my reels in good old cold tap after the Photo-flo.