Unicolor 4x5 processing drum

[KevinVH]

Hi everyone, it's been a couple of years since I was active here on the forum but I recently was gifted a very nice but basic 4x5 camera, along with all the equipment to develop, and I shot some sheets last week. I just mixed up some D76 and Arista fix to develop the Efke PL 100 M film I shot.

I've got a Unicolor processing drum along with the little "machine" to agitate the drum while developing, but I can't find out how much liquid I need to pour into the drum.

This is the kind of drum I have, can anyone recommend a manual, or tell me how much liquid I need to pour in?

I also found, according to the massive dev chart I need 7 minutes at 20 degrees celsius for a stock D76 with the Efke PL100M, does that sound about right?

 

[shawn]

Fill the drum with water and put it on the rotator (fill side over a sink) and turn it on. After it finishing draining out measure how much water remains in the tank.

Shawn

 

[KevinVH]

Fill the drum with water and put it on the rotator (fill side over a sink) and turn it on. After it finishing draining out measure how much water remains in the tank.

Shawn

That's a great idea, can't believe I didn't think of that, must be the emotion of developing my first sheet film!

 

[Mike 5714]

You really want to use as little developer as possible, enough to do the job but no more. For developing 2 4x5s in a drum, I use 300ml.

There's been quite a bit of discussion over the years at the large format forum site about just this kind of thing and you might get more and better information there.

 

[randy stewart]

You really want to use as little developer as possible, enough to do the job but no more. For developing 2 4x5s in a drum, I use 300ml.

There's been quite a bit of discussion over the years at the large format forum site about just this kind of thing and you might get more and better information there.

These drums were designed to process color paper, using chemistry in a one-shot and discard method. There's no apparent reason you could not use one to process film, and if prior owner did so without issues, great. If you want to fill the drum half full and reuse chemistry, then it really makes no difference how you use it, and the "fill it to overflowing" advice above is fine. As a matter of economy, you want to use the minimum amount required by the surface area of film being processed. In a traditional film tank, the requirements of filling the tank almost always are greater volumes than required to process the film, but in roller drums, the physical amount required to just cover the film or paper is so low that you must consider the amount of developing agent required instead. The film manufacturer's data is probably the best resource for that data. A second issue is that while a certain volume of developer may be enough to cover the film in the drum, as it rolls it sets up wave patterns which may result in uneven processing. To avoid this you may need to use a bit more solution. Finally, that drum/roller base combination must be FLAT. Use a good level to make sure the drum is very flat when rolling, so the solution inside is distributed evenly.

 

[rjbuzzclick]

This is how I develop all of my 4x5 film, up to four sheets at a time. I use 250ml of solution to get the required 5ml minimum amount of Rodinal concentrate at 1+50 (actually 4.9ml but close enough). It works really well and no issues with uneven development.

The only other consideration is that in my experience the spouts are not quite as light tight as something designed for film would be. I just don't let the film sit in the drum too long before processing. Basically I load the film in the dark right before developing, then turn on the room lights except for the light fixture directly over my work surface, and then process. I don't have any light leak issues even with pushed 400 speed film.