Uneven development?

[tom_mccabe]

Good afternoon, all. I'm running into some issues and would like some opinions. Attached is an image I shot at Fort Fisher in Wilmington, NC on  bright sunny day. The camera is a Toyo 45CF, 210 MM lens. I developed the negative in a Yankee Tank loaded with 7 sheets. I used Ilfotec DDX for 7 minutes. Several of the sheets showed this same problem, though of varying degrees. This one was the worst. The camera has a new bellows and no apparent light leaks. It looks like uneven development but I'm not sure. That particular tank cannot be inverted so agitation is a side to side sloshing action. My agitation was 5 seconds every 30 seconds. I'd appreciate any thoughts. I just purchased a Stearman SP-445 but haven't used it yet. This is a straight scan of the negative.

[AJG]

I think your diagnosis is correct--It looks like uneven developing due to poor agitation.  I have successfully used a Gepe sheet film tank but didn't like it since it leaked and took way to long to fill and dump  chemistry.  My ultimate solution is a Jobo sheet film tank that can do 12 sheets at a time on  a Uniroller rolling agitator.  5000+ sheets later it still works and is what I would recommend.

[tom_mccabe]

Thanks!!

[Alan Marcus]

You can check for light leak easily.  Place a small keychain flashlight inside the camera. Sit in the darkroom with the camera on your lap. Waite for your eyes to dark adapt, about 15 to 20 minutes. Examine the camera from all angles. What leaks in also will leak out!

[chris_autio]

 I have had uneven development with Yankee and Jobo processors with sheet and 70 mm films. Your example shows this inordinate density throughout center of sheet. The best results I had were nitrogen bath processors. To do my own, I use tray processing, thin gloves. Trays sitting in larger trays such that temp stays steady. Carefully lift bottom sheet to top, laying it easily. Turn entire group (up to eight sheets) 180 half way through. Make sure there are only smooth surfaces throughout whole process. 

[AJG]

32 minutes ago, chris_autio said:

 I have had uneven development with Yankee and Jobo processors with sheet and 70 mm films. Your example shows this inordinate density throughout center of sheet. The best results I had were nitrogen bath processors. To do my own, I use tray processing, thin gloves. Trays sitting in larger trays such that temp stays steady. Carefully lift bottom sheet to top, laying it easily. Turn entire group (up to eight sheets) 180 half way through. Make sure there are only smooth surfaces throughout whole process. 

I had uneven development with 4x5 film with my Jobo 2500 series tank at first when I attempted to use it like a conventional processing tank with inversion agitation.  I called Jobo and they advised rotary processing on a roller (mine was from Unicolor) and then taking the tank off the roller once per minute for about 5 seconds and inverting it 3 times within that 5 seconds.  They also suggested lengthening the development time to 10 minutes or longer, which I did with a custom dilution of HC 110 arrived at through testing. There were no more issues after that through the 5000+ sheets of 4x5 Tri-X that I developed with that tank and roller combination. These were not the directions that came with the tank, however.