Processing drums

[Curtis Nelson]

I've been thinking lately of purchasing a motor base and drum to use for 4x5 B&W film processing, and I was hoping someone could answer a few questions for me. 1. Will any drum work with any roller? 2. Are there any daylight drums that can be used with a roller? (by daylight, I mean one which allows me to fill and empty chemicals without opening the drum in darkness) 3. Is there a particular drum better suited for 4x5? 4. Are there any special inserts I need to purchase to process multiple sheets simultaneously? 5. Any advice on best base/drum combinations?

Thanks for your help

[Bruce Watson]

http://www.jobo-usa.com/products/3000.htm

[David Karp]

http://www.largeformatphotography.info/unicolor/

[Nick_3536]

1) No

2) Jobo 2500 [except the very smallest one]

3) religious issue

4) For the 2500 type you need a reel. Each reel handles 6 sheets. Bigger tanks can hold more reels. The smallest tank thatt will fit a roller holds 2 4x5 reels for a max of 12 sheets.

5) religious issue-)

[Darin Cozine]

First let me say that the uncolor type drums are very different than the jobo system. I think the Unicolor, Beseler, Omega/Chromega, and Cibachrome print drums are all very similar.

1.The unicolor type drums just sits on top of the rollers of the base. I think most will work interchangeably. One difference though is how they keep the drum centered on the roller. I have a chromega motor base which needs a rubber ring around the center of the drum. But it's pretty easy to adapt something to keep the drum in place, like a vaccum cleaner belt or even a rubber band.



2. I think all the print drums are daylight safe, so once you load the film, you can do the rest with the lights on. It is reccomended to use the Unicolor 8x10 print drum. I have a Cibachrome drum which is totally smooth on the inside (like the Unicolor film drum). But I have never had a problem with the anti-halation coating not coming off of the film.



3. I think most of these drums are made for doing 8x10 (or larger), I've never seen any which were designed for 4x5. Sooo....



4. for all of these you will need to find some way to keep the negatves separated in the drum. You can try GreyWolf's way as illustrated here (http://www.largeformatphotography.info/unicolor/) I glued surgical tubing to the inside of my drum, but the tubing was hard to work with, I may try rubber weatherstripping next.

5. The older/cheaper motor bases just continuously turn the drum. It is reccomended to pick up the drum and reverse it about once every minute on these. The better motors will change directions periodically, or add a rocking motion. This allows for really easy proessing.

In summary, all of these Unicolor type proecssors are designed for 8x10s, but with a little adaptation will work wonders for 4x5.

[Louis Jensen]

The unicolor 8x10 drum will hold 4 4x5 or 2 5x7 pieces of film. With 4x5 film you need to make sure that the pieces of film do not slide together. Use a thin plastic pinch pin or bend down a corner of adjacent pieces of film; e.g. about 1/16 of an inch.

[d.s.]

Curtis,

I went through this same thing a while back and I settled on the following for $35.00 from ebay.

To process up to four 4X5 negatives in a "daylight" drum, I bought a "Unicolor" motor base model #352. It auto reverses. For a drum you need a Unicolor 8X10 "Paper" drum.

There are other systems but I think they are more expensive.

[Jon_2416]

If you go the Unicolor route (I love mine, perfect negs after a bit of experimenting), don't mess with weatherstripping. Just get some 1/8 thick hard rubber and cut yourself a spacer. I have a photograph of an original one I will email you if you wish*. My 'copy' of the spacer works great.

*I posted the spacer image to photo.net also, so you can search the archive there and find it. I would post a link, but PN is suffering one of its many down periods at the moment.

[Bob Fowler]

The photo.net page that Jon mentioned is here:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=007A4L

[Darin Cozine]

Thanks for posting the link.. My choice of material for a spacer would be plastic cut from one of those AOL Cd cases I get in the mail.

[jantman]

Jobo.

Once you try it, you'll never go back. I started using one to do Ilfochromes, now I use it for rollfilm, 8x10 film (in the 2840 print drum), and, of course, Ilfochrome. They're great. Makes things a lot easier. I have the plain old CPE. One with a lift would be nice, though my timing is pretty good. The one problem with the CPE is that the temperature needs to be adjusted by trial-and-error. But only when switching processes.

My dream is to get a Jobo Autolab. It would make doing film a lot easier (you don't need to be there, so you can dev film once you get back from a shoot, while you're grabbing a bite to eat).

[jantman]

Oh, yeah, one other thing. If you also shoot rollfilm and get the Jobo, you can buy a bigger drum that will do 6 or 8 rolls of 120 at a time.

The Jobo drums that I use use 240mL of chemistry for either two rolls of 120 or one sheet of 8x10. If you want to do 4x5, you HAVE to get one of their more expensive Expert drums.

[Nick_3536]

4x5s fit the 2500 tanks just fine. The tanks will also take an extension so you don't need to buy a bigger tank to do more film.