AGO Film Processor - Automatic For The People

by Huw Meredith

No, this isn’t a very belated review of the 1992 REM album, but a look at the new AGO Time Compensation Film Processor which is a way to get more consistent results when developing film for beginners and experienced workers alike.

My Film Processing Journey: 45 Years of Experience

I have been processing film for over 45 years, starting as a hobby, then professionally, and even after I changed to digital in 2000, I still enjoyed going back to my roots and putting films through the old gear. The last few years have seen a major resurgence in analogue photography and many people are looking to get into processing their own films.

Understanding Time and Temperature in Film Development

Processing a film is a chemical reaction, and like all such reactions depends on a relationship between time and temperature, Yes, other factors such as different proportions of developer, or altering the film speed can make a difference, but for this demonstration I am using the given film speed of the film (box speed) at the recommended processing times given by the manufacturer of the developer. For most films, development is recommended at 20 degrees Centigrade (68 Degrees Fahrenheit).

For this test, two rolls of Ilford HP5 Plus, which is an ISO 400 Black and White film were exposed using a Nikon FM2 camera and an 85mm lens. All the exposures were the same and the subject was lit by a Phottix T200R LED Tube Light. The subject matter wasn’t really important as all the exposures would be the same, but I thought I would keep it film related.

For those who are interested, while the HP5 Plus in the camera has a healthy 3 years left before its ideal “Process Before” date, the ten films in the photo are “Out of Date” by a combined total of 339 years! They range from a roll of Konica VX 200 colour film from 2008 going backwards to a roll of Ilford FP3 black and white from 1968. And yes, with the exception of the obsolete roll of Kodachrome slide film, all the other nine WILL get used at some stage.

When I say that Kodachrome is obsolete, I do acknowledge that it is possible to obtain black and white negatives from such a film using quite a complex and fairly hit and miss process, not something I will attempt, this roll can stay as a museum piece.

The Importance of Consistency in Film Processing

The complexities of trying to get some pictures from that roll of Kodachrome bring us back to the importance of good housekeeping when processing our films. We need consistency, and if you can learn to be consistent with your first rolls of film, it will put you in good stead for the future. Is my developer new or in good condition? Are the mixing jugs for the chemicals clean so that there is no contamination ? Can I be accurate when measuring out the correct ratios of chemicals to water? Will I be able to get my developer close to that benchmark figure of 20 degrees centigrade? You will have to learn to do the first three yourself, but the AGO will cut out the problem of variations in temperature.

The AGO Can Save You Money on Chemicals

The films were processed in Ilford Ifosol 3 Developer. The Ilfostop Bath and Ilford Rapid Fixer bottles were from my own darkroom, and might not be exactly the same as current labels.

The Ilfosol 3 was diluted to the ratio of 1 + 9 with water. For the first 2 films which were processed in a conventional Paterson developing tank, this equated to 30mm of Ilfosol 3 to 270mm of water to give 300mm of working solution. The AGO requires slightly more (325mm) for one film, however when processing multiple rolls in the AGO, then savings on the amount of working solution can be made. This is because the AGO works in a horizontal format as opposed to vertically processing a Paterson tank.

Developing in the Paterson Tank

Half of the first film was cut from the spool in the darkroom and loaded onto a film spiral and put into the Paterson tank. If you don’t have access to a darkroom, then a Film Loading Bag can easily be used. The temperature of the Ilfosol 3 working solution was 20 degrees centigrade and this was checked using a Brennan Electronic Test Thermometer, but you could use any darkroom thermometer.

The Developer was poured into the tank and the timer started. The recommended developing time suggested by Ilford for the combination of HP5 Plus at the box speed of ISO 400 and the ideal temperature of 20 degrees centigrade was 6 minutes 30 seconds. The film and tank were inverted for 5-10 seconds every minute and gently tapped on the worktable to avoid air bubbles. After the Ilfosol 3 had done its work, it was poured into a larger container for disposing of later on at household recycling centre, and replaced for 1 minute by the Ilfostop stop bath. Developers are alkaline and the acidic stop bath immediately prevents any further development.

The stop bath was replaced by the Ilford Rapid Fixer for 5 minutes and after the fixer was returned to its storage bottle (the stop and fixer can be re-used several times) it was followed by several changes of clean water. Ideally get the temperature of the wash close to that of the fix and lower the temperature down to that of the cold tap over the next few water changes. The mixing ratio of the Ilfostop working solution is 1 + 19 (so 15mm mixed with 285mm of water) and the Ilford Rapid Fixer is 1 + 4 (so 60mm to 240mm of water).

Testing the AGO Processor at Lower Temperatures

The second half of the first film was then given exactly the same time of development in the conventional Paterson tank, but this time it was at 15 degrees centigrade.

My initial reaction was there wasn’t a huge variation in the 2 sets of negatives. I felt the recommended combination of 6 minutes and 30 seconds at 20 degrees centigrade to be over developed, and the ones developed at 5 degrees centigrade lower would be slightly easier to use. I altered my plan slightly and cut off a small amount from the next film and developed this at 10 degrees centigrade, a whopping 10 lower than recommended. Sadly, I had only cut off a very small section of film, but it showed that although the neg was definitely underdeveloped, it would still provide some sort of print or scan. What it actually proved is that new stock Ilford HP5 Plus is virtually indestructible! 

Anyway, this doesn’t really matter, even though the “ideal “combination negs seems over developed, the whole point of this exercise is to see how well the AGO coped with the films.

How the AGO Processor Handles Agitation and Temperature Compensation

Half of the remaining film was loaded into the AGO tank and the closed tank firmly placed onto the AGO processor. Three Holes have been drilled by AGO into the lid for pouring in (and out) of the working solutions. These have to be at the bottom as the tank sits on the processor. AGO provide a template so that you can drill out your existing Paterson tanks.

AGO recommend that processing times for rotary processors are reduced by 15% to compensate for the constant agitation, so this meant the standard time at 20 degrees centigrade would be 1 minute less, ie; 5 minutes and 30 seconds.

Putting the AGO Film Processor to the Test

I really wanted to test the AGO from the outset, so I put in the Ilfosol 3 developer at 10 degrees centigrade. This again was checked by the Electronic Test Thermometer. (Ok,I hold my hands up, it actually went in at 10.1 degrees).

The freezing cold developer is poured in. (OK, a slight exaggeration there...)

The AGO works by having an internal thermometer probe always in contact with the working solution. It does not heat up the solutions. For years all the major film makers have supplied charts for darkroom technicians to manually work out the different time/temperature combinations that deviate from the normal benchmark of 20 degrees centigrade. I still have my own dog eared and chemical splashed version on my darkroom wall from the days when I would be using a 15 litre Developing Tank in the depths of winter. Instead of warming up all that developer, it would be easier to alter the time, however the lowest my chart went to was 13 degrees centigrade, and I don’t think I ever went that low anyway! AGO have incorporated these charts into the “brains” of their clever little machine, How well would it perform?

Finally, you see the AGO, isn’t it great? but does it work?

Does the AGO Film Processor Deliver Consistent Results?

Within a few seconds the AGO has decided that 5 and a half minutes just isn’t enough, and has extended the processing time to over 13 minutes. This was very close to the figure that my very old graph was telling me after I had made allowances for the lowest temp of 13 degrees not being low enough.

The Ilfostop was followed by the Ilford Rapid Fixer and the film was washed. What happened?

Well, the AGO had produced a set of negs that were almost identical to my first manual set, the ones I reckoned were a bit overdone, but that didn’t matter at all, I was looking to see consistency between the 2 sets. Any slight difference will most likely be down to the constant (and reliable) agitation that you achieve with the AGO.

More Testing Ahead: The AGO Film Processor in Action

My final bit of film was going to go in at the benchmark temperature (you must surely remember this by now) of 20 degrees centigrade. Just going through the motions really? Well no, because the AGO had another surprise in store for me.

Although the developer went in at 20 (you know the next bit.. ) the ambient temperature of the inside of the AGO tank must have been less, not much, just 1 degree, but the AGO still decided to compensate by an extra 30 seconds or so. As we have seen, you can do a lot of bad things to Ilford HP5 Plus, and it still comes out a shiny happy film (another REM theme..), but not all films are as robust, Pan F Film also from Ilford probably needs more careful handling for example.

How Easy Was the AGO to Use?

Considering that this was only my first and second ever times using the AGO, I was pleased with how it went. The display was easy to use and to navigate. However, I would like to practice my pouring in out of the working solutions a bit more. My second film in the AGO seemed to take longer to pour out (the developer) which probably added more developing time than the first film, but practice makes perfect.

The AGO has to be perfectly dry before using again, but that would apply to a conventional Paterson tank anyway.

Just a reminder that the AGO needs slightly more solution than I was using in the conventional Paterson tank 325mm as opposed to 300mm. Also, if you have never loaded a film spiral before, it’s not a bad idea to sacrifice an old scrap film and practice in daylight first. Remember to trim off the film leader before loading.

A Closer Look at the Results

Results time… possibly not as important as all those 16/17 year olds waiting for their exam results in August, but still important for the little AGO machine.

Notwithstanding the slightly uneven illumination of my hastily arranged home made light box, the manually developed set of negs (B) clearly haven’t had the same development as the others. The AGO has altered the time to compensate for the much lower temperature in set C, really well. The final set done in the AGO do differ slightly from the other AGO set, but as I mentioned before, I think I took too long to pour out the developer and get the stop bath in.

AGO Film Processor - Final Thoughts

The AGO performed really well, and I am looking forward to using it for developing Colour Neg (C41 process) which requires a much higher temperature accuracy and ultimately Colour Transparency ( E6 process) which requires even more accuracy than negs! 45 years ago,I worked in the Middle East and had to manually process E6 films using ice cubes to get the temperature down to the correct level. (I won’t go in to the occasional power cuts and the cockroaches and lizards that cohabited on the ceiling…). How much I would have given for an AGO machine back in those days. The AGO has default settings for various Developing Kits available for B&W, C41 and E6 or you can use your own custom settings.

The AGO Film Processor is available now at The Flash Centre.

Would I buy the AGO? It’s already on order.