In hopes of drawing answers from all who might have encountered this problem, I posted the same question on the Apug.org. Different people and different answers have appeared. If interested you might want to read:
http://www.apug.org/forums/forum37/1...m-problem.html
John
Thank you all for your suggestions. Some contradicted others so I did my best guess of what to try first. Ideally I would make one change at a time, but there were simply too many, so I took a chance. Since my last post I developed the film in four holders and got significantly better results. By that I mean the edge density is still there, but much less in size and tone. Following are the things I tried. Please give me your thoughts as to how I can improve the process.
Level tank: grhamp ….”make sure it is level and rotating on-axis.” The 2800 series tanks are two cylinders with a rib joining them together at midpoint. I made sure the water level of the Jobo was lowered so the tank rested on the rollers. The rollers hold the tank on axis. The 9” level I use for setting up the camera is perfect for testing this because it fits either side of the central rib. Good idea, but the tank was level and aligned, so no improvement here.
Fill water at 68 degrees F, 20C. PE suggested this instead of the 70 degrees F I was using. Arbitrarily I increased development time from 6 minutes to 6:30. This later proved too long and I reduced it to 6:15 minutes.
Sal Santamaura gave this link to his posting on new and old Jobo speed settings. http://www.apug.org/forums/viewpost.php?p=1610856
Prior to reading his post I had been experimenting with reducing the speed from “4” to the first notch to the right of “F”. In doing so the problem became larger and darker. I returned to “4” and with these other changes things got better. Sandy King suggested reducing speed as far as possible, so I still have experiments to do there.
Sandy wrote, “What I have found to be the Number 1, Number 2, and Number 3 solutions to this problem are, 1) weaker dilution and longer development time, and 2) slower rotation, and 3) lift the drum very early in development and rotate it up and down, and repeat this every two or three minutes.” I started by trying #3 every 3 minutes. After the first two batches with the speed set at “4” I tried two batches set a “3” speed and noticed an improvement.
PE suggested a stop bath after development. Bostick & Sullivan’s instructions for Rollo Pyro say “At the end of development dump the solution and do two quick water rinses in a period of one minute.” I used water.
keith schreiber suggested, “If your drum is a 2850, there is about 21 inches inside from end to end. If you are not already doing so, try positioning the film so that it is centered rather than inserted all the way.” I did try this. Unfortunately after the rotations Sandy suggested the film worked its way back to the bottom of the tank. Perhaps because the film was at midpoint for some part of the development this helped, but my first rotation was at one minute.
Larry Gebhardt suggested, “You might try flipping the film around (notches to the bottom). That would let you see if it's a light leak in your camera.” I did this on every other sheet and found that the increase density was always on the bottom of the tank edge regardless of where the notches were. This was very helpful because I had gotten several suggestions that the problem was either in the film holders or the camera.
In the original post I said, “I have ten film holders and the problem exists which ever film holder I use so I doubt it is a light leak.” I have since realized that I was only using four holders from one bag. This test batch of development was done with the same holders reloaded with the same type film, HP5+. There has been a significant improvement. Thank you all for your help. Based on this newer data what next steps would you suggest?
John
"In the original post I said, “I have ten film holders and the problem exists which ever film holder I use so I doubt it is a light leak.” I have since realized that I was only using four holders from one bag. This test batch of development was done with the same holders reloaded with the same type film, HP5+. There has been a significant improvement. Thank you all for your help. Based on this newer data what next steps would you suggest?"
Have you eliminated the possibility of a camera light leak? There could be a light leak that would fog the end of the film on every holder.
Sandy
For discussion and information about carbon transfer please visit the carbon group at groups.io
[url]https://groups.io/g/carbon
Thank you Sandy. How would you do that?Originally Posted by sanking
One reason I don’t think that is the cause is that in three of the last four development tests I remembered to turn around one of the two sheets so that the notch was toward the bottom of the tank. Regardless of the orientation there was an equal amount of higher density on the edge of the film closest to the bottom of the tank. This density lightened as the test progressed. Of course the problem with changing multiple factors is I don’t know if one or multiple changes caused the improvements.
I plan to try your other two suggestions as soon as we have some sun in Cleveland and I can shoot some more images.
Thank you.
John
One of the suggestions was to center the 17” side of the film in the 22” tank so the film rested above the bottom of the tank. In my recent tests the film slid to the bottom of the tank during development, probably because I tried Sandy’s suggestion of rotating the tank.
I thought of a way to make these two ideas work and would appreciate feedback your opinions. I have some scrap developed film. I thought of cutting two 2x7” sections and feeding them into the tank to the bottom and then feeding in the undeveloped sheets. If the larger sheet jumps over the smaller I can try two smaller overlapping sections in the future. Does anyone know enough about flow dynamics to anticipate what effect this will have? Will I create different agitation?
We are supposed to have some sun Monday and Tuesday. Perhaps I will be able to make some new or replacement images to try. Your thoughts will be appreciated.
John
To check on possible light leaks from the camera, insert a holder in the camera as you normally do, put a light inside the camera, and close off the lens board. Now turn off all lights and, in total darkness, walk all around the camera to see if there is any light coming out, either through the bellows, around the back where the holder is inserted, around the area where the bellows attaches too the camera, around the lens board, etc. Allow your eyes 10 minutes or so to adjust to total darkness. If there is any light coming out of the camera, it could get in to the film.
If there are no problems with light leaks I would recommend using a dilution and temperature that would allow you to develop your film to the desired CI in about 12-16 minutes instead of your current 6-7 minutes. Shorter development times can amplify any issues caused by turbulence or agitation procedures. Years ago someone I know taught a workshop with ULF cameras and several of the participants were experiencing uneven development in drum processing. He mentioned that the one change that solved all of the problems was changing from the use of D76 straight to a 1+4 dilution of D76. It was necessary of course to increase time of development significantly, but the dilution itself eliminated nearly all of the problems.
Sandy
For discussion and information about carbon transfer please visit the carbon group at groups.io
[url]https://groups.io/g/carbon
Sounds like it's almost certainly a turbulence issue from the end of the tank. I think Jobo made clips to hold film or paper in place in the 2800 series drums, but I haven't see or used them. I did try making some out of cut plastic years ago and they popped off every time. If you can't find any of the Jobo clips you could make a stop for each side out of Sugru. It's a moldable silicone product that air hardens and is then dishwasher safe, so it should hold up to processing. I imagine a small blob of it at the bottom of each side of the drum (in the middle) would keep the film from slipping, and if molded over the ribs should stay put. Try to keep it low profiled so it doesn't create much turbulence. It's a shame there isn't an expert drum you could use for that film size.
Sandy,
Thank you. I tried the flashlight in the bellows. After about seven minutes I found the slightest sliver of light. There is a rectangular wooden stop for the film holder that is fastened in place by a screw at top and bottom. Both screws were loose after several years of knocking about. That eliminated about half the light.
For the time being I have used a strip of gaffer tape to seal the crack. I will talk to Dick Phillips about a more appropriate fix. I am guessing remove the rectangular piece and add some padding. All that will show then will be an edge rather than the tape.
I tried the fix with one of your holders and one from Lotus, the two brands I had been using when I discovered the problem. After ten minutes in the dark, no sliver of light. Thanks for taking the time to share your expertise.
Next I will talk to Dana at Bostick & Sullivan about diluting Rollo Pyro and how much to increase the development time. There is still the question of why I got edge density on the notch side when it was turned to the bottom of the tank.
Thank you.
John
Now that winter and Cleveland’s grey skies are behind us I have been out shooting, developing and printing 7x17.
“One of the suggestions was to center the 17” side of the film in the 22” tank so the film rested above the bottom of the tank. In my recent tests the film slid to the bottom of the tank during development, probably because I tried Sandy’s suggestion of rotating the tank.”
The Jobo clips and the mesh bags that Jobo in Ann Arbor made do not seem to exist for 7x17. There are some for sale for 11x14 on eBay from Israel, but nothing for 7x17. The idea of trying to insert in those and then the tank in the dark is not really attractive to me.
Several ideas of ways to hold the film off the bottom of the tank involved restraints that might have made their own turbulence. I had an idea that is simple, free and involves no modification to the tank or difficult loading. I cut two inches off the end of a failed 7x17 sheet of film ( I had quite a few of those) and inserted it in the drum before the undeveloped sheet. In 12 developments of 2 sheets at a time, 8 times the 2”stips have stayed in place even after the rotations. When the strips have popped out during development, the 7x17 sheets have stayed in place, two inches off the bottom.
The true test was printing. Each negative developed with the two inch strip in place has printed evenly, ie: without a lighter edge on the side of the negative near the bottom of the tank.
I am really happy with this result and wanted to offer it to anyone suffering with the same problem. Thank you all for your suggestions and especially Sandy King for the detailed instructions.
John
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