On processing large format film

Film is sensitive to light – that’s necessary for it to work. Exposed film (unless so grossly overexposed as to change colour, just as things can bleach after very prolonged exposure to sunlight) looks the same as unexposed film. To produce an image, it has to go through a number of chemical steps which also fix the image and ensure that the film no longer reacts to light, making the image permanent. At least some of these steps have to take place in conditions that won’t expose the film. For panchromatic film, that means no visible light, and for ortho film, red light only. For black and white, there are only two chemicals involved, first a developer to turn the exposed film black and a fixing step which removes any unexposed emulsion and leaves the unexposed parts transparent. There’s a rinse between these steps, and a final wash, but that’s it. Quite simple, except for the part about light exclusion (which is only necessary until the end of development).

Daylight development tanks are (or have been) made for all film sizes from subminiature up to 10×8, and only require the film to be transferred into them in darkness. Other methods are available for all film sizes which do require absence of light, but daylight tanks are the only practical method without a darkroom. If you do have access to a darkroom, ortho film can be processed using a red safelight so you can see what you’re doing and how the development is progressing. With panchromatic film, although the room must be dark, some people work using infra red goggles, which enable them to see in the dark. Clearly, a red safelight (with ortho) and IR goggles (with pan) can be used to load tanks in a darkroom. Without a darkroom, you have to use daylight developing tanks and load the film using a changing bag or tent. I use daylight developing tanks, and load them in my darkroom before processing them in the kitchen.

I use changing tents when away from home to load and unload film holders; when home, it’s simpler to just use the bench in my darkroom. I have two changing tents: this is my Harrison Pup tent, which is intended for film sizes up to 5×4. Larger sizes could be used, but the advantage of being able to easily lay out the items is reduced. The film and other items are placed inside and the double flap zipped before inserting my hands into the two elasticated sleeves which let my hands into the tent while still excluding the light. A changing tent is easier to use than a bag, because the tent structure keeps the material away from the objects inside. I have the larger Harrison Jumbo for 10×8 film, but note that even the small version fills this table…

As far as I know, sheet film only has these methods available for development.

Methods that need a darkroom

1. Open trays (requires a darkroom)

This is the oldest and cheapest method. Film is developed in dishes (multiple sheets are possible at one time) and there are You Tube videos demonstrating how to do it. It is possible to develop smaller formats in a similar way, holding the two ends of the roll and see sawing the film through a trough. Needs must, but although illustrated in older books, I’ve yet to come across anyone who has done it!

2 Deep tanks (require a darkroom)

These are just what the name suggests – tanks, as many as the stages required by the process. The sheets are held in hangers or clips, and moved along the line as required. Tanks with floating lids are very convenient, in that (assuming thermostat controls on the temperature) they are always ready for use.

3 Nova Print Processor (requires a darkroom)

A similar concept to the deep tanks above, Nova make three and four slot processors with floating lids. I have a four slot processor for making prints, and they are very convenient. As they are always ready for use (they have a water bath and thermostat) it’s possible to pop into the darkroom and make a print with no setup or clear up steps needed. Film rather than paper could be used in the paper holders, and the film developing chemicals used instead of print ones.

Methods that can be used in daylight.

These divide into methods that require special tanks for sheet film, and those can can use tanks that also can be used for roll and 35mm film

1 Special tanks for sheet film

4 Paterson orbital

This is no longer made, so only available on the second hand market. Originally designed for producing colour prints without having to carry out all the step in the dark, it can be used for 1 sheet of 10×8, 2 sheets of 5×7 or 4 sheets of 5×4. You may also come across a motorised base, which releives you from having to keep rocking it during processing.

5 Stearman Press tray

Similar in concept to the Paterson Orbital, with the same film capacity. This is a recently introduced device, and features very rapid emptying and filling.

6 CombiPlan tanks

These are also no longer made, due to the moulds wearing out and being uneconomic to replace. They can take up to 6 sheets of 5×4 film at a time. The main disadvantage is that they do take a long time to fill and drain, about 30 seconds for me. I generally take the lid off to make for more rapid drain and filling at the end of the stop bath stage after development.

7 Artifex tanks

These are made for 5×4 and 10×8 film, and can take up to 6 sheets at a time. Reducing frames are available to allow 5×4 to be processed in a 10×8 tank. Although they do require a large volume of chemicals, blanking plates are also made to cut the volume required by one or two thirds, if you aren’t processing six sheets.

8 Yankee and Doran tanks (5×4)

These can take up to 12 sheets of film, but the volume of chemicals required is high. Additionally, agitation during processing is best carried out by rocking the (rectangular) tank.

9 Stearman Press SP445

5×4 only, economical on volumes, but only 4 sheets at a time.

10 Jobo Expert system

This consists of waterbath, motorised agitation, and special drums to process sheet film. It is rather expensive…

2 Methods that can use 120 and 35mm film tanks

The final methods make use of developing tanks used for smaller formats. If you already process your own films in smaller sizes, the chances are you already have a developing tank, and can continue to use it.

11 Taco method

Never having tried taco, I don’t know how many sheets could be fitted at a time or indeed much else about it, so I’ll ignore it. It is certainly the cheapest in equipment terms. All you do is use a rubber band or hair grip to curve the film round (emulsion side in), and place it in the tank. This seems to be a popular first step, and a means of seeing if you want to go all the way with LF before spending more than you absolutely have to.

12. Special reels that can be used in Paterson and Jobo tanks

Several different devices are sold by various manufacturers which can hold from 3 to 6 sheets of film (of sizes between 9x12cm and 10×8 inches) in an unmodified tank. Although not all are available in all the sizes, there is at least one insert for all the large format (but not ultra large format, defined as larger than 10″x8″). These include both Imperial and the metric sizes. Makers include:

  • Catlabs
  • MOD54
  •  Jobo
  • 20th Century Cameras

Subjective thoughts on methods

For 10×8, the Paterson Orbital processor and Stearman trays are one sheet at a time, Catlabs and 20th CC 3, Artifex 6.
Paterson and Stearman are continuous agitation which increases grain and reduces acutance effects (I use Rodinal which is an acutance developer); Catlabs and Artifex allow inversion agitation which I’ve always used.

Comparing Catlabs and Artifex, Catlabs potentially requires more chemicals, as the tank will need the same amount whether 1, 2 or 3 sheets are processed. Artifex allow the tank to be blocked off if less than two sheets are used, reducing the amount of chemicals required to 1 litre for two 10×8 sheets.

I’m a born worrier and pessimist. On that very subjective basis, the Catlabs spiral worries me that the film could be misloaded or come adrift in processing, 10×8 being rather more “floppy” due to the size than 5×4. The Artifex holders do secure the film on three sides, and the space inside the tank means sheets can’t physically rise out of the holders.

Moving down to 5×4, the contenders are much the same, with Catlabs dropping out (I don’t know if they make a 5×4 – they may do) but with CombiPlan, the various Yankee type tanks, Jobo spirals, Stearman’s SP445, MOD54 and 20th Century Camera spirals coming in.

Yankee (I have a Doran variant) allows up to 12 sheets at a time, but always requires a full tank of chemicals. For me, use only if I have a lot of sheets to process.

CombiPlan have been reported to have problems with uneven processing if 6 sheets are loaded, so I have always limited it to 4, the same as Paterson and the Stearman. Jobo spirals can be a little more fiddly to load (easier if you buy the loading accessory), 20th Century Camera spirals are easy (and they make 5×7 as well) and take 6 sheets.

Loading and filling times are longest with CombiPlan at around 30 seconds the way I pour. The methods that use a standard Paterson or Jobo developing tank (20th C, MOD54, Jobo reels) are faster. In fact, all other methods with the probable exception of the Yankee tank (down to the volume) are going to be faster.

My interest in the Artifex 10×8 came down ultimately to a matter of convenience and nervousness. Convenience, as up to 6 sheets of 10×8 could be processed in one go (I develop for around 16 minutes, so multiple times through takes up time) and I had no worries about sheets detaching (in theory). Other 10×8 methods were one or three sheets maximum. Having seen what the 10×8 version was like, I did get the 5×4, on the basis of a reliable 6 sheet at a time method. I’ve often had multiple times through sessions with the CombiPlan (I have about half a dozen of these tanks…).

Just for completeness. As I’m now using 5×7 more than 5×4, I’ve had to investigate methods of daylight developing for this size, and options seem more limited: Jobo drum, 20th Century Camera, Stearman tray and Paterson Orbital. Preferring inversion to continuous agitation, that only seems to give one option. The 20th Century Camera spirals look flimsy, but hold the film and are easy to load even with the larger sheet size.

Apart from the four figure sum required for the Jobo Expert system (and over £500 for the special drums to go with it), the most expensive method here in terms of capital cost is the Artifex at almost £500. All the others come in at under £200, and usually at about the £100 mark if tanks, and half that if spirals or reels for a Paterson or Jobo tank. Is the Artifex worth the price? That would be your decision. I do know that if you’re going to be moulding something, the cost of moulds is horrendous, and is the reason that CombiPlan tanks, Walker Titan cameras and Paterson Orbital processors are no longer made. New moulds required, costs too high when set off against potential sales. This could explain somewhat the price. On the other hand, even if the Artifex is a expensive, it is still only 3-4 boxes of 10×8 film. Price v convenience is always tricky.