4x5 drum development questions

[derek_5869]

Hi,

Well I went ahead and got myself a 4x5 Pacemaker Speed Graphic, and am now having some trouble trying to figure out how to handle development myself. After reading on the largeformatphotography.info site about using Unicolor drum and roller I thought that sounded about right for me. I was able to secure a Uniroller but actually finding an 8x10 Unidrum has proven to be quite difficult.

Today I walked into a local camera store and found a Chromega 8x10 print processing drum so I bought it. This drum has three cylindrical tubes which run down its length and in between which you wedge the print/film. These are similar to the v-ridges in the Unicolor drum. The problem that I'm concerned about with this Chromega drum is that there are no ridges along the walls of the drum, so the backside of the film can touch the walls. When the film is loaded between the tubes the backside of the film gets very close to the walls of the drum. I've practiced loading the film several time and and can't find a way to insure that no part of the film is touch the wall of the drum. Now since most of the film isn't touching the wall, is that enough for the chemicals to get back there and do their job? The Uniroller reverses itself something like every 1.5 revolutions.

So I'm wondering if this is ok for drum development, or will it cause problems with not enough of the chemicals reaching the back side of the film. Does anyone have any thoughts about this? Is presoaking the film likely to begin working on the anti-halation layer on the backside of the film?

I noticed that in the manual for the BTZS tubes it looks like the film is actually touching the walls of the tube, so maybe this is ok??

Thanks in advance, Derek

[mark blackman]

I don't know about thus particular drum, but I've used the equivalent Jobo print drum to develop 10x8 E6 and B&W film with no problems.

[resummerfield]

The Chromega drum should work fine. As you notice, the BTZS tubes are smooth, and the film back is in tight contact. Some people recommend a piece of fiberglas screen between the film and tube, but I’ve found that more trouble than it’s worth. The chemistry only needs to contact the emulsion side of the film. If you experience any “mottling” on the backside (usually in T-Max films), wash the film in trays with a clearing solution. I would also recommend a water presoak for more even results.

[Brian Ellis]

I've used BTZS tubes in 4x5 and 8x10 sizes for years. The fact that the back of the film touches the walls of your Unicolor drum won't be any problem. You can leave the film in the drum when you're using the stop bath but be sure to remove it and fix it in trays. The back of the film will look funny, very milky and splotchy, when you first remove it but after it's been in the fix for a while that will disappear.