4x5 Unicolor Drum Development

By James Phillips (aka GreyWolf) © 2002 for the Large Format Page

For beginners to large format film it is often asked how you process your sheet film. I hope here that I may provide you with one alternative to consider and the one I have found to be both the easiest to do as well as producing the most consistent results. When I first began to do my own development the first method I tried was tray processing. Ansel Adams in his book "The Negative" had convinced me that this simple method was both cheap to perform as well as easy to learn. I am sure that after enough practice anybody could do this well but for myself I did not like working in total darkness and I also found myself frequently scratching the film surface during the shuffling of the sheets in the solutions. I then read about using a Unicolor 8x10 paper print drum which I already owned. Once I tried the drum I was hooked. So let's begin....

The first thing that you will require is an 8x10 paper drum and also the roller machine both made by Unicolor. Even though these are no longer being made they are quite plentiful in the used market. Check you local camera store or else look on Ebay as there is always many to be had there. The important part is not to confuse a Unicolor film drum with a Unicolor paper drum.

Notice the elastic bands I place around the drum to keep the drum from sliding off the rollers when turning.

The paper drum has raised ribs on the inside so that the solution can reach behind the film where as the film drum is completely smooth on the inside. Also be sure to get the Unicolor drum and not some other brand as this is the one that works properly and permits multiple sheets to fit comfortably inside. What you will discover is that you may place four sheets of 4x5 film inside a drum if you have a proper spacer. The picture below shows the spacer I was able to easily make out of a clothes hanger I recently purchased from Wal-Mart. I use the other hangers in my darkroom to dry 4x5 sheets. Just hang the sheets by the corners using the clips that are on the hangers.


You can easily see the clip above that I removed from the hanger and trimmed for a spacer. 

This is the clip I made to use as a spacer in the drum 

Original Unicolor sheet film spacer. Photo courtesy of Tim Atherton  

When you place more than two sheets in the drum you need to keep them from sliding over each other during the development process. There are many suggestions on spacers but I have found the one I made above is both very easy to use and make. Just take one of the clips off the hanger and trim the tip like the picture above with a small coping saw. Then file the burred edges and you now have a clip that will last for years. You need to trim the clip because it is too wide otherwise. This clip takes about ten minutes to make. When using the clip just place two films in the drum (one on each side) then pinch open the clip (in total darkness of course) and slide it down the "V channel" inside the drum until it bumps against the two films in the drum. Actually quite easy to do and the clip stays put during processing. 

Two sheets being placed in drum

Just slide them to the bottom of the drum and then put the clip on.

(Obviously you do this in the dark)

The clip fits over the "V channel" 

If you look closely you can see the space between the sheets of film being provide by the clip

There would be two sheets at the bottom and two more above the clip.

By this time you would have four sheets of film in the drum with the spacer between them and the lid securely on the top. You can now turn on the lights and develop the in the comfort of room light.

What I have done for my B&W developing is dedicate 500 ml brown jars to the developer, stop batch, and fixer. I have also bought very cheaply four plastic measuring cups that hold 500ml (or 2 cups) of liquid. As you can see by the picture below I color code both the jars, stirring sticks (which are plastic chopsticks) and the measuring cups. This ensures that I do not cross contaminate anything in the processing of my film. Also notice the plastic water pitchers (like those used in restaurants) that hold wash water in the background. 

Red is developer. Blue is Stop Bath. Green is Fixer.

The unmarked measuring cup is for a pre-wet.

Notice the water jugs in the above picture. When I am mixing up my developer (I use a one-shot method) I also fill my pre-wet cup as well as the two water jugs. I then have the pre-wet at the correct temperature when I am ready to begin. The water jugs also have the proper temperature water and this permits me to do the film washing without ever having to turn on the water and adjust the temperature. Only when I am ready to dip my films in the wetting agent in a Tupper ware container is when I need to run the water again. I do this because as I progress through the developing stages I can wash all my containers and put them away for next time. This really minimizes my clean up time and also permits me to do archival washing by using many rinses of water. Click here to read about archival film washing.

In regards to my color scheme I use vinyl tape to mark the jars, cups and other things. Below is a picture of the package of tape that is easily obtainable and cheap in my area from Canadian Tire stores. If you are not able to find tape like this then you may email me and I’ll see if I can help you.


The nice thing about the measuring cups is that you do not need other measuring devices to measure your water out, the cups are easy to pour in the drum, the drum is easy to empty back into the cups and finally the cups are easy to empty back into the bottles. I only do this for the stop bath and fixer. I do use a small measuring graduate to measure out the developer solution when mixing up the working dilution of my developer.



As you can see by now this drum processing method is both simple and elegant in that you can process and clean as you go. Also the ability to minimize the times you need to set water temperatures is an added bonus. The cost of the additional plastic measuring cups and the water pitchers is so minimal as to negate that issue.

Solution Quantities

For those of you who may not know how much minimal solution is required I can offer you the following. First I have the original instructions, which refers to the minimal requirements for paper developing. This is the minimal amount of liquid required to properly cover the paper when the drum is turning. Instead I choose to make sure I far exceed the minimal as one-shot film developer is reasonably inexpensive to use.

What I did to determine the maximum amount that may be used was to partially fill the drum (without film inside) and then place it level while using a Plexiglas end to stop the water from running out. This permitted me to see how much liquid I could reasonably put in the drum without going above the flanges on the bottom side of the film. I wanted to ensure that the developer (or other chemicals) would not touch the film if the drum was level and would only begin to get the film wet when the drum began to spin. In other words what I do is fill the bottom trough while the drum is closed and with it sitting level on the motor base. Of course you must make sure the feet are facing down for this to be effective and the almost certainly are as the spout faces up when in this position.


Developing E-6 Film in a Unidrum

Some people may cringe at this idea but I have also figured out a way to develop E-6 film with regular success in this Unidrum. The most important thing to remember is that temperature variations are quite critical in developing "chromes" so that if you are consistent in your method you can be successful. I also wish to clarify that I do photography purely as a hobby so I do not have client’s expectations to contend with. On the flip side of the coin I thoroughly enjoy doing all of the processing myself at home and take pride and satisfaction in knowing that I am self sufficient in my hobby. In my area I can buy Agfa E-6 (500ml kits) for about $14.00 Cdn. and this will do eight sheets (2 cycles) in a Unidrum. At a $1.75 per sheet this is slightly less that would I would pay in town. I am also able to do the processing as soon as I get home from a day shooting if I want and get to see the results that very evening. So let’s read about the technique I use.

Step one is to get the chemicals to stay at a constant temperature before processing and be able to keep them near the proper temperature during the steps that need to be done. I do this by using a hot water bath that I have made inside a small cooler. My procedure is to heat the chemicals to 102 degrees and when they come out of the drum they are 98 degrees giving an average of 100 degree Fahrenheit.

Here is a $8.00 cooler I modified to heat the bottles

I place the lid on when the chemicals are the correct temperature of 102 degrees.

The lid ensures they stay at this temperature for at least a half hour. 


Here you can see the holder I made for the bottles in the cooler. 

Also you can see that I have also developed a color scheme for my E-6 processing.

The brown bottles are 250 ml each which is a perfect size.

The next step is to ensure that the drum is pre-warmed with the film inside. This is actually easier to do than you might think. You just heat the drum in a pail of hot water that is at least 105 degrees Fahrenheit. By holding the drum in the water (with the spout and lid seam clear of the water) I am able to make the plastic drum quite warm in about 3-5 minutes. Surprisingly the drum temperature is not as critical as I thought it would be but rather just as long as the drum is good and warm so it does not cool the first developer when it is first placed in the drum. The first developer is the most important step in developing E-6 film in my opinion. The first developer will determine if the “chrome” comes out too dense or too light. Too hot or too long will cause the “chrome” to be too light in appearance. Most of the color shifts that people experience when developing E-6 films are related to other issues and not the first developer temperature.

Do not let the water come up as far as the lid seam but get as close as possible.

I colored the water for the picture so you could see it. 

Now when your chemicals are at the proper temperature of 102 degrees Fahrenheit and you drum is pre-warmed by the water batch you can begin to develop the film. The only other concern I had was that the drum would cool down as it was spinning in the air. (I wipe the water from the drum after the pre-warm bath so as not to cool the drum via evaporation).  What I did to keep the drum warm is to place a gooseneck lamp with a 100-watt light bulb over the drum during the processing. This worked amazingly well and my chemicals hardly lost any temperature from the time they went in until the time they came out. The developer after 7 minutes comes out of the drum at 98 degrees Fahrenheit.

            As you can see I am doing an average of the two temperatures to obtain a 100-degree developing temperature for the first developer. The second step is a water rinse batch and I usually put in 500 ml of 102-degree water to keep the drum up to temperature in preparation for the color developer. After the color developer has completed the temperature is not critical and as it slowly drops off it will not affect you density or color of the film. The most critical is the first developer for proper density. The color developer is then the second most critical and should be within a degree or so of 100 degrees for a proper color with out a colorcast or shifting of the colors. Once again this is much easier and more forgiving than most people are led to believe.

 Unidrum II Official Instructions:

The Unidrum instruction sheet says the following (for paper as this is a paper drum).

1.      Single Large Print – minimum of 60 ml of solution (2 oz.)

2.      Several small prints – minimum of 120ml of solution (4 oz.)

3.      Minimum wash volume per rinse – 180ml of water (6 oz.)

Note: (as per directions) Unidrum must be used on a LEVEL surface … Chemistry will not cover the entire print if Unidrum and/or roller are not level. If surface is not level chemistry requirements should be doubled to insure proper chemistry coverage.

In my testing you can place in the drum a maximum of 200ml of solution (when the drum is level) before the fluid starts going over the bottom vanes and touching the edge of the sheets of film. Obviously when I do developing I use at least twice as much solution as this and it does not seem to have an adverse affect or create edge development effects.

I hope you have enjoyed this article and find potentially some benefit here in helping you do your own development. If you have a drum already and can buy an economical small developing kit then I recommend you give this a try for yourself. You may surprise yourself with the good results that you can obtain with a little patience and having fun at the same time.

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