HELP processing with a 3005 expert drum problemgreenspun.com : LUSENET : Large format photography : One Thread
Over the past few months I have dove into the 8x10 format. After reading every post and comment imaginable I decided to get a Jobo drum to use on a besseler motor base to process my film. So here is the problem. I am having parts of the film not getting chemicals to it so part of the film is left pink and undeveloped. I am loading the film with the base to the outside and it has happened with and without presoak. I am using a bent funnel to pour in the chemicals. I am using d76 with Hp5. I have gone through the process of loading film doing a test shot on the porch souping the film and it has happened every time. I have called Jobo and talked to a gentleman there but he basically said I need to get a cpa, etc. That the tank is not meant to be used on anything but Jobo stuff. Needless to say, that was not much of a help. Thanks in advance for any input.
-- Echard Wheeler (Ew1photo@aol.com), January 15, 2001
There is another entry just at the bottom of all the list of recent entries which is about processing 8x10 into a jobo processor, read it and follow the Links indicated by Sean Yeats.Greetings.
-- Andrea Milano (email@example.com), January 15, 2001.
The Guy from Jobo is correct. The reason you need the processor with the expert drum is that the drum MUST BE laid horizontal and be spinning when the chemistry is poured in. If you can make a way to accomplish this without the processor and lift, then you should be able to avoid your problem. Also, use enough chemistry per the Jobo guidelines for the drum. If the drum is not spinning, it will not distribute the chemistry evenly on the film while it is being poured in.
-- Gary Frost (firstname.lastname@example.org), January 15, 2001.
I use the 3010 with 4x5 and have never had a problem. as mentioned, the secret is horizontal orientation, constant rotation, and sufficient chemistry. I used to simply pour the chemistry in from the top, set the drum on the cradle, and hand rotate for the duration. one time, I noticed a slight density gradient caused by pouring developer in without rotation. I since have gone to more dilution, in general, and a long-necked funned to add chemistry during the developer phase.
-- daniel taylor (email@example.com), January 16, 2001.
While it would be optimal to have the drum spinning while pouring the chemistry in, I don't think this is Echard's problem. You appear to be loading the film correctly, that is with the emulsion side curled inward, or film base towards the drum walls, however you may not be spinning the drum correctly. I am not familiar with the Besseler motor base, but for the 3005 drum to work properly the direction of rotation must be reversed every 5 to 10 seconds.
Other things to consider... Make sure you're using at least the minumum amount of chemistry for the tank AND the minimum volume per square inch of film. These capacities are listed on the tank and on the film/developer data sheets. If the drum isn't turning when the chemistry is poured in/out, try and minimize the time to pour the chemistry and get the drum spinning.
-- Pete Caluori (firstname.lastname@example.org), January 16, 2001.
I use a 3005 on a Unicolor 352 motor base. I had to modify the base switching because the large drum was not making a complete revolution before reversing. You should be using a reversing base. Are you getting a complete turn from the Beseler? I ended up setting mine for approximately two turns before switching.
-- Chuck Pere (email@example.com), January 17, 2001.
If you increase the volume of chemicals one part of the problem will be solved. I have successfully processed by rolling the drum on a table surface. Not a desirable way to do this, but by using extra liquid it works well. One added benefit of using more chemistry than the minimum is in making sure you have enough stock solution to assure full development for the full development time. I have also successfully used the big drums by rotating in a water bath to help keep temperatures constant. "Minimum" amounts of developer and other chemicals are just that. Any deviation from the ideal JOBO system use and you have no safety margin. Use more than the minimum. Try using at least double the amount of stock the chart says you can get by with.
-- Dan Smith (firstname.lastname@example.org), January 17, 2001.
I just wanted to clarify my last post, as I agree totally with Dan Smith's response. I did not intend to imply that you should use the minimum amount of chemistry, but that you should use at least the minimum. Erring on the side of more would be better.
-- Pete Caluori (email@example.com), January 17, 2001.
I just wanted to thank all of you for helping me find out what I was doing wrong. I wasn't switching the rotation. It was that simple. I was just letting it spin in one direction. So now I spin it for a minute one way then pick it up and switch direction. It's a pain but it works. Thanks again.
-- Echard Wheeler (Ew1photo@aol.com), January 18, 2001.