Questions on Unicolor drum 4x5" processing

[John H. Henderson]

I just got a Unicolor 8x10" drum and a model 352 motor base. I thought I read t his recommended on this site, something saying that the unicolor drum would take 4x5" sheets. Sure enough, it has slots that will hold 4x5 sheets.

I have questions, but first I want to say that this is the most fantastic thing I've bought. I've been experimenting with different processing techniques. Sta rted with trays (nasty, possibility of scratched films, working in dark, hands c hanged chemical temps), went to combi-plan (can't get chemicals in and out fast enough. Leaky leaky leaky.), then to hangers and Kodak 4x5 tanks (Working in da rk. Too much chemical to discard after every use. Mess pouring back into bottl es.), but then tried this drum. Oh, it's nice. I can discard the chemicals aft er every use, so I'm not adjusting times for depletion or replenishing, and it's nice to let the machine work while I go load the dishwasher or watch TV since I don't have to agitate.

My first question: Does anyone know what amount of chemicals I should use in th is tank? Does anyone have instructions? I have no instructions with it. My fi rst test sheets have been done with 250ml. The Tri-X/D-76 looked pretty good us ing the development time in the Kodak instructions. My TMX/D-76 don't look so g ood, but it may have been the exposure. Anyway, the tank doesn't seem to hold m ore than about 500ml, or it spills.

My other problem is if I put two sheets in one slot, one will often slide under the other. At first, I thought this was because I was little too vigourous hold ing the drum on end and shaking out chemicals, but even after being more gentle, I was still ahving this problem. Does anybody have any secrets or have rigged something to keep the sheets from sliding under each other?

Anybody have any starting processing time suggestions for TMX and D-76 with this drum? Mine seem a little thing using Kodak's times. (Now that I've settled on a processing method, it's time to do some serious testing and calibrate my proc ess.)

(Please don't suggest that I buy a $400 Jobo drum or I should use some exotic co mbination of paper and developer that must be packed in on llama from Nepal. I am a beginner who wants to get reasonable results with what's easily and financi ally available to me. I'll do the exotic stuff later.)

[Don Sparks]

John, I use a Unicolor drum for processing 4x5 Tri-x in Xtol 1:2. I had to cut the recommended development time quite a bit because of the continuous agitation. I think you will like the Unicolor drum processing, but you will have to do some testing to see what works best for your film and developer. Somebody else's dev. time might not be the best for your system.

[William Marderness]

The Film Developing Cookbook suggests 250ml of full strength developer per 8x10 sheet. Many will think this is too much, but this is the practice I follow. This means that 500ml of D-76 1:1 is right for four 4x5 sheets.

[bob moulton]

John You might consider using the Jobo drum system on your Uniroller base. Either the 2500 series, which allows developing up to 12 sheets, or the expert series-the 3010-that allows up to 10 sheets processed simultaneously. These avoid some of the problems you mention. As for amount, I use 900ml of chemistry in the 2500 and in the 3010 series. With d-76, that's 450 ml developer. You can use less if you are not processing the drum full. Bob Moulton

[N Dhananjay]

The films are likely to slide across one another when loaded in the same slot. Stick to processing one on each side. I cut up a piece of plastic so that I can slide it over the chemistry trough ridges. This serves to keep the sheets separated. Load one sheet on each side, slide the plastic in, load another two sheets on each side. DJ

[Erik Ryberg]

John,

If you got your drum used, it is probably missing the little plastic thingys that separate the two sheets that go in one slot. You need them to keep the sheets from sliding together. It's bad news, but I suggest you process only two at a time unless you have them. This will allow you to use extremely dilute developers though, so look at it that way.

I follow Jobo's instructions of giving a 3 minute water bath prior to development and then using more or less the same times I use for roll film in a tank and by golly it works.

Your negatives with TMAX are probably thin because TMAX basically has no latitude whatsoever for underexposure. But it has immense latitude for overexposure. My recommendation: shoot the stuff at 50. Your negs will be fine. A still better recommendation (many others will disagree with this one) is to quit the TMAX altogether and shoot FP4 or some other standard emulsion. I have much better luck with them myself and prefer their look. At 4x5 there is little need for a fine grained film like TMAX unless you are making pretty big enlargements. If you are choosing it for its look though, well, that's another story. Good shooting.

[John Hicks]

The minimum solution to cover is 2 ounces, but don't even think about that. Use at least 8 ounces.

Unicolor provided a little rubber divider with the drums to keep the sheets ap art. It's a little block of soft rubber that has a v-shaped cutout in one side t hat slides down on the v-shaped rib at the "top" of the drum. You put in two she ets to the bottom of the upright drum, slide the rubber thing down the ribs unti l it just touches them, then insert the upper two sheets. Get a little block of soft rubber, 1/4" thick and 1/2"x1/2" and experiment.

For TMX in D-76 1:1, try around 10'45"/68F. Over the years I've found that abo ut a 10% reduction in development time from intermittent agitation is an appropr iate starting point for rotary agitation.

BTW, if you get any unevenness or streaking, try D-76 1:3 at about 1.4X the 1: 1 time.

[Yaakov Asher Sinclair]

I would be interested to know where you can buy a Unicolor drum and how much they are. Many thanks

[james mickelson]

I cut a wooden stick to keep the film apart. I think anything will work as most bUnicolor drums are used and the divider is the first thing that is lost. I use 100ml for two sheets and 200ml for four sheets. But unless you have calibrated your system I would up it to 150ml and 300ml respectively. Many fine art photographers use Tmax and love it. It will look thin if you are used to TriX, fp4, hp5 or PlusX. These are thick emulsion films. The Deltas and Tmax film are thin emulsions. They print beautifully. But the secret to great prints is calibration. Calibrate your entire system from film choice, exposure through processing film and printing. It pays off in a very short time. You will love your drum. James

[John H. Henderson]

I bought it used (but it looked completely unused - the seller didn't know if had been or not) but it did not include any dividers. I will fabricate some sort of divider.

As for where to find them new - beats me. I've never heard of or seen a unicolor base or drum until reading this board. I can't find a web site for unicolor. I've never seen them in any photo store. I got mine off of eBay. I paid $15 for the 8x10 drum and $31 for the 352 base. If you're patient, you might do better. I wanted it NOW, so put in bids to ensure that I got it.

Thanks for the guidelines for solution amounts. Now that I've settled on a processing method, I am about to run the calibration process in Steve Simmons' book. (Which made little sense to me when I read it before buying the 4x5 and developing stuff, but now that I've played for 8 months, makes good sense.) I also have a $5 gift certificate at Amazon, so I ordered The Film Developing Cookbook.