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[ejkanter]

I'm going to attempt developing a few sheets this weekend.
This will be my first time developing with 4x5's.
I'm going to be using the unicolor paper drum with the motor base.
Any suggestions on chemicals and or times to use for this?
Any help would be appreciated.
Thanks,
Erick

[sauerwald]

I do my 4x5 processing in a Jobo system, which uses drums much like the print drums. The issue is that when drum processing you have a large ratio of surface area to volume for the chemicals, which makes temp control difficult. To get consistent results in film processing, you need to keep consistent temperature.
The Jobo, and another method - BTZS tubes - get around this by keeping the drum in a water bath which maintains temperature for you.

BTZS tubes are little drums - the usual ones are made from 2" schedule 40 pipe with end caps on each end. The basic idea is to put your developer in one cap, then, in the dark, load your film into the tube and put the tube on the cap - now you can turn on the lights, and when ready to start, lay the tube in a tray of water where you roll it back and forth. In the dark, or subdued light, drain the developer and replace with stop, then fix.

Things to look out for:

Make sure to load the film with the emulsion side in.

You can use very small amounts of chemical for a sheet of film with tubes since you dont have to completly immerse the film in the chemical. This makes the method very economical, but it doesn't work well with very dilute developers which are quickly exhausted - I have had issues with Pyro and Rodinol - D-76 and HC-110, no problems. For Pyro, I just use more developer.

With a large print drum I would be concerned with keeping the film stuck against the walls of the drum so that you get even development.

Just an aside - tray processing of sheet film is not that difficult.

[45PSS]

What film and what developer are you planning to use? Kodak and Ilford give times for continous agitation in their film spec sheets. Try 15%-20% less than standard intermiten agitation times as a starting point if no other information can be found.

As far as temperature is concerned, if developing at 68⁰ and the room temperature is 70⁰~72⁰ then a 1⁰ temperature change is about all you will encounter in 30 minutes and well within tolerance for most films/developers, however processing at 68⁰ in a 85⁰ room you will achieve the 1⁰ temperature change in a few minutes. I place the chemicals in a sink of 68⁰ water that covers 75% of the bottle at the start of the processing cycle and have a bucket of water the same temperature to do the dilution mix and washes with so I only have to do the final wash with running water from the filtered tap.
Charles

_________________
Graflex Corp.was a (silent) supporter of Rain Forest Devastation.



[ This Message was edited by: 45PSS on 2006-04-13 23:07 ]

[ejkanter]

Thanks for the help.
Yes, it's Kodak film. I'm still working on setting up a room to be used as my darkroom so for now doing daylight processing is easier.
Erick

[45PSS]

Go to http://www.kodak.com and click on Pro photographer/lab tab then click on product information then click on the film that you are using then on the tech pub link for that film, downloadable in pdf also. Current list is Tri-X, T-max, Plus-X 125, High-speed infrared film for black and white.

_________________
The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

[glennfromwy]

When using the Unicolor drum, be sure to make some provision to keep the film from creeping one over another. Most folks make spacers to go between sheets to prevent this from happening. As mentioned, adjust your developing time to compensate for rotary processing. 10 to 20% less than recommended times may be needed. I find most listed times to be too long anyway. For a huge volume of processing info for different film/developer combos, visit http://www.digitaltruth.com
An 8 X 10 Unicolor paper drum uses about 4 ounces of workng solution. Good luck and let us know how you do, eh?

_________________
Glenn

"Wyoming - Where everybody is somebody else's weirdo"

[paulownian]

I have been processing all of my film in a Phototherm processor for the past 3 years. They are much less expensive than other automatic processors and give great results. As mentioned in another posting, temperature is a major concern, so I rely on the Phototherm to heat the chemicals, one at a time, inside the processor. I have had great results with consistency, used less chemical in the long run, and have made my processing completely (except for the initial loading of the film) automatic. Once I have loaded my film into the tank, I simply turn on the machine and push a button. I am setup for B&W, C-41 and E-6 at the push of a button. All of the chemicals are stored in plastic containers beneath the machine. I never worry about mixing prior to processing. I only have to do that once I have used all of the stored chemicals. I can even process without the need for a water supply if I choose as this system has a water supply container along with all of the other containers. I can also choose to capture a particular chemical if I want to replenish. You can usually find one of these machines on ebay, or let me know and I will give you the info on the company I purchased from. ...just thought you would want to check out this great processor while you are building your darkroom.