Thursday, 25 October 2012

Rondinax and Rondix: Daylight Developing Tanks

It is often forgotten that it was — and still is — possible to develop films without having to use a darkroom or changing bag. Most developing tanks sold in the UK had to be loaded in the dark, a process often accompanied by curses as the film jammed or buckled in the reel or chinks of light were spotted around the shutters that were used to cover the windows of a temporary darkroom.

I was given my first developing tank by a great-uncle who had bought it in the 1930s. This Agfa Rondinax 60 was for 120/620 films and I used it for black-and-white films until the 1990s. The Rondinax 60 was a brilliantly designed and constructed but simple daylight tank. No darkroom was necessary. It was also extremely economical to use because the volumes of developer and fixer needed were small. Rondinax 60s, to judge by the prices they reach on eBay, are still a popular purchase for those still using 120 back-and-white film. The only disadvantage was that the spiral had to be rotated continuously (with the recommended short, jerky movements) during developing, rinsing (stop bath) and fixing. However, I see somebody has arranged a motor drive to automate the turning (which I think goes a little too quickly) and a video of it in action is on Youtube:

Instructions for the Rondinax 60 can be found at:

The 35 mm equivalent was the Rondinax 35 U, also marketed by Leica as the Leitz Rondinax 35, particularly in the USA. Both these tanks had black plastic spirals. The film was dragged onto the spiral by a belt of ‘American cloth’ (rubber-coated cloth) along a plastic film guide. The rubber on the cloth perishes with age but the fabric without the rubber continued to work well for me.

The Rondinax 35 had a stablemate, the Rondix 35, which worked without a spiral and again entirely in daylight. Photographs of the tank are are at:

The Rondix is far less well known than the Rondinax but was much cheaper to buy. My grandfather bought one around 1957 and, again, I used it until the late 1990s. In this tank, the end of the film is attached to a small central drum and the film wound into the tank from the cassette until the entire film is tight on the drum and resistance is felt on the winding handle. Then the handle is reversed so that the film turns back on itself to become wound on the drum in the opposite direction. When resistance is felt again, the direction is reversed, and so on until developing and fixing are complete.

The film, therefore, sloshes around in the developer/fixer and is never in contact with another loop of film for more than a few seconds at most. I have made a quick diagram to show the principle.

How the Rondix 35 Developing Tank Works without a spiral

Instructions for the Rondix 35 are at:

The Rondix 35 was clearly not so popular as the Rondinax 35 (and neither as popular as the cheaper, vertical tanks that needed to be loaded in the dark). We wondered then whether people thought the film, not being held on a spiral, would be more likely to get scratched but we never found that to be the case. In fact, the Rondix tank and filtered developer produced some of the cleanest negatives I ever produced.

I had several Agfa Karat cameras which used special cassettes for cut lengths of 35 mm film. The film passed from cassette to cassette as in a roll film camera but without the backing paper. I thought the Rondix could not be used because the end of the film was not held in the cassette. However, I see in the more recent instructions that Agfa Rapid cassettes could be used (again, the film was not held). In this case one is instructed to do so many turns to the left and then so many turns to the right, and so on, in order not to pull the entire film into the tank. I would not liked to have risked losing count.

Only two sizes of Rondinax/Rondix tank were produced: for 120/620 and 35 mm film. The significant omission is, of course, 127 and for that size, a darkroom-loading, vertical, ‘universal’ type of tank was needed. I had a Rolleiflex 4 x 4 in the early to mid-1960s and black-and-white processing had to wait for a visit to the darkroom. I had been spoilt by the Rondinax 60 and the Rondix. Daylight-loading 127 tanks were made by an Austrian firm before the second world war and imported after the war but I never saw one advertised.

I never tried reversal processing in these tanks. There was no transparent spiral in the Rondinax 60 to allow exposure to light. Reversal processing may have been possible in the Rondix if a glass or transparent sheet had been held over the film in place of the lid. Turning the handle (with water in the tank) so that light reached the whole film may have done the trick. Again, I did not risk it. The Polly-Max tank I used for 127 films was used for reversal processing of Ferraniacolor.

Informative websites on the history of these tanks are:

Post second world war copies of the Rondinax 35 (the ‘Essex’ and 60 (the ‘Kent’ were made in a collaboration between Johnsons of Hendon and Neville Brown (NEBRO) in the early 1950s, presumably from designs and patents confiscated by the allies. I have never seen one and the advertisements must have been before my time. By 1955, Agfa was in full flow advertising the Rondinax 35U and the 60 as the advertisement from the BJ Alamanac for 1956 shows (the BJ Almanac for a particular year appeared, as I recall, in the preceding autumn). I think the Rondix 35 appeared the next year.