Are you extremely consistant with how far you roll the drum back and forth? If so that has the possibilty of making uneven density from stopping at the same point all the time, especially if the roll is short. A nice long roll that stops at random points of the drum might help some.
You know it's funny I just found this thread.
I've had the EXACT same problems you are having using those drums. I have the unicolor plastic tubes with the one fill end, and the other the dump end. The tube is nearly perfectly smooth on the inside. I use the tubes on the rotor base however, so the agitation is always consistant. I presoak about 5 minutes for each film.
The weird thing is, the developer rotates around the film one directions...but the streaking is always the complete opposite dirrection on the film!!!
I processed over 300 sheets of JandC Pro 100 in Pyrocat-HD 2-2-100 in those unicolor drums on the unicolor base from my Iceland trip, and did not get any streaking. However, I did a few negatives this weekend and the streaking is AWFUL! I really do not understand it. Same film, same developer, same EVERYTHING...just different subject matter images.
Someone suggested that you use a piece of nylon screening on the inside of the tube to slide it in and out. I tried this, and the streaking still happens.
I've tried everything from changing presoak time, developer dilution, temp, development time...but the streaking is still completely random.
I'm sorry I cannot provide an answer for you, as I am seaching for one myself. I'm just going to go back to using trays again for the time being, but using those tubes is great if you do not have a dark/wet enviroment.
Anyway you could scan a print made from one of the negatives, or scan the actual negative?
I'm going to scan one of my prints from the streaky unicolor negatives and will post it here tomorrow. We can compare how they look.
Which direction are the streaks going?
Have you tried flipping the tube around (so that the rotation is effectively reversed) during the development?
I only process paper using the tubes, but I do that reversal flip every 30 seconds.
There was a post on the Mamut Photo Forum about density banding for Efke 100. I have had the same problem with Efke (7X17 format); and am wondering if they've had a quality control problem. I'm also using J&C 400, and process in tubes on a Uniroller as with the Efke, but have no problems.
van Huyck Photo
"Progress is only a direction, and it's often the wrong direction"
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wish I could offer something other than what has been suggested. I process 4x5,5x7 and 8x10 in a Beseler drum (while not the same thing is very much the same process). They are all processed in a 8x10 drum, on a drum motor (Unicolor - auto reverse). While I have had other problems, not this one....wonder if it is something with the films.
process is 250ml of water for pre-soak, 250-300 ml of Pyrocat 2+2+100 for x minutes, 250ml of water stop for 1 min, then 250 ml of fix (Ilford rapid fix) for 4 mins. Drain, pop the top and wash (fill, soak and dump x times). No sign of any streaking. I know Lee uses Unicolor drums for his negatives and have not heard of any problems (though he is not using Efke now). Will continue to watch this thread...most interesting.
My process is EXACTLY the same with the exact same amount of chemestry. I'm using the same dilution, same water stop, same Ilford fix and everything else. I have a few different drums, some are Beseler, some Ilfochrome, some Unicolor, however...I compared them and they are all exactly the same thing.
Originally Posted by photomc
I'm going to post a scan of a recent image that was destroyed by streaking.
Here is a scan from a recent negative I developed that showed the streaking. As you can see,I have streaks that go horizonally, and then a huge square area of density change that goes vertically on the left side. The sheet of film was placed in the tube in a horizontal position, and rotated with the developer inside in the horizontal position, so the streaks that go horizontally do not make sense because the developer does not flow in that way.
I checked my tubes with a piece of film, and the film lays smoot and flat on the inside. The streaks are clearly on the emution side, not the base side. The film was not fogged or exposed to light, so that is not the cause for the uneveness in the development. Nor is it the paper, as you can see them on the negative. (EDIT- Do not confuse the texture of the paper with the streaking bans)
Please post images of your problems as well, so we can compare the two.
I think it has something to do with your agitation process. You can get very good consistancy with a cheap unicolor motor base (available on ebay) and a gadget used in the woodworking industry to vary router speeds. http://www.mlcswoodworking.com/order.../speedcon.html. I just plug the unicolor base into the speed controller and slow the rotation down. Its very consistant and much more economical than an a jobo
Have you considered the possibility that your problems could be a quality control issue with the film? It seems very odd that your process would work like a charm for 300 negatives and then suddenly you get lots of streaking in your negatives. One of your variables would be the film. I would suggest trying a sheet developed in a tray and trying a sheet of different film with your tubes. I know folks love to bash Kodak on these forums, but I've never experienced a QC problem with Kodak products.
Good luck in your quest to solve this issue. Please keep us posted of your findings.