I am getting a fair number of emails on development time in a Rondinax because of the difference in agitation. I have nothing to add on my original post which can be found here. If anybody has information to add on particular film/developer combinations please let me know.
Over the past month I have had a number of emails and comments from people who have bought Rondinax tanks and then found the film guide was absent. The film guide is essential so please look at the BUYING TIPS in the bar above for advice on how to check that all the parts are there. Many sellers on eBay are not aware of what they are selling. The film guide is the one item most likely to be missing.
I have received the following. I have never processed a colour negative film in my life and so I am hoping for replies to come in.
Comment: Hi, my name is Thomas and I am a industrial-design student from Germany.
For my Bachelor thesis I am currently tackling the negative colour development for home usage as I have been suffering of keeping the temperatures on myself. So the aim right now is to make an easy kit which heats and stirrs the chemicals to a desired temperature both before and during the chemical process and to automate the rotation/agitation of the film in the tank.
During my research I came across your great website and ever since then I really want to include the ‘daylight tank’ technology into my project.
I would be more then thankful if you could spare some minutes to help me with a few quastion.
1) The daylight tanks have disappeared for quite a long time and have quite a bad reputation among some users. Do you think this is due to the lack of the slide film possibilities at that time? Or because it can only load one film at the time? Or maybe ecause of ‘less contrasty/sharp’ image results? Or because of some difficulties while developing colour negatives?
2) As I am completely rebuilding the tank I thought of maybe adding the option to load two 35mm film at the same time or even make a universal tank for both 35 and 120mm films. Do you think that would be a big point for people considering switching from JOBO to a daylight tank solution?
3) Would you still consider the Rondinax 60 a good solution to go for although of a lot of complaints about films not working or would you recommend to stick to JOBO tanks instead for 120mm?
Quite a lot of questions but I do hope that you could give me some insights before I will take a wrong turn.
Thank you already for your time and effort.
Have a nice evening and all the best
How many Rondinax users and potential users are out there? I will start by showing the viewing data for this site.
2013. 808 views by 180 different people
2014. 12,779 views by 3,360 different people
2015 so far. 4993 views by 1419 different people
The people viewing in different years could be the same, so these data suggest there are more than 3,500 in the world who are interested in daylight-developing tanks and who have found this site.
The viewing figures for the videos on YouTube suggest about 5,000.
Leading the popularity stakes on YouTube is the video on the Rondinax 60 with 5240 views. This confirms my suspicion that the majority of Rondinax users are medium-format film users. The Rondinax 35 follows with 3547 views. The short video on how the spiral loading works has 1323 views; how to use the Essex 35 has 983 views. The Rondix video has 990 views.
These figures illustrate the level of interest but do not answer the question of how many Rondinax, Essex and Kent tanks are actually in use or in a condition fit to be used.
I read in somebody’s blog recently that he had had trouble in getting the film to load into the spiral and had ruined a film. I must admit that I have never has such a problem and I can only assume that the instructions in the manual had not been followed to the letter.
The instructions in the 1964 edition of the 35U manual (available under DOWNLOADS above) are probably the best. There are several stages that could be of critical importance, including cutting the film leader off absolutely at right angles to the length of film and between perforations, then cutting a bevel off the corners, and turning them slightly inwards. The manual does not explain what inwards means but I turned them towards the emulsion side. It is equally important to attach the clip in the centre of the film. There is a recess in the tank to hold the clip in the centre. However, I preferred to close the clip with the cassette and spiral reel out of the tank. That way, I could check that there was an equal width of film on either side of the clip and that the film was pushed firmly against the back of the clip.
Before I sold my 35U, I did see what the effects were of not getting the clip central and of not cutting the film off at a right angle. I used an old length of film and watched what happened with the lid off. Sure enough if the film was skewed in the clip, loading into the spiral could fail at various stages in the length of a 36-exposure film.
Those with an Essex tank will know that the preparation of the film and attachment to the band are different. It is more of a hassle but in that tank the clip (which is not a clip but a buckle) really does hold the film in the centre.
I think it is a case of read—and follow exactly—what it says in the manual.
Thanks to Suzy Richards we now have the supplementary pages from the manual of the Essex Mark II 35 mm tank. The manual is identical to the Mark I with the addition of these supplementary pages.
The supplement describes operation of the tank with Leica Type B labyrinthine film cassettes which have to be opened before the film can be withdrawn. Unlike the Rondinax 35U, the special Zeiss Contax cassettes cannot be used in the Essex.
For users of modern standard cassettes the presence of the left-hand knob on the Essex Mark II, just as on the Rondinax 35U, can be completely ignored. How many users of the old Leica and Contax cassettes are there now?
I have had a few queries on whether I have any experience of using caffenol developers in Rondinax tanks. I have never used caffenol but somebody out there may be using it in their Rondinax. If you have used caffenol let me know, or comment on this post, remembering to state the mix, the temperature, the time and the film, and then others can benefit from your experience.
As I slowly sort out the tanks I have bought to illustrate this site, I have put another two on eBay. The first is a Rondinax 60 (Item Number 171225664246) in excellent condition. The seond is an Essex 35, the one I used to make the YouTube video on this tank (171225666860). It is also the one described in my post of 27 October 2013. The auctions end on Sunday 2 February.
I had a message from a recent purchaser of an Essex tank to say that the thermometer had broken and could his washing it in hot water be to blame.
The short answer is yes. The thermometers in these tanks are designed to work over a short range. If the temperature is too high, the alcohol expands but, being a liquid cannot be compressed. Therefore, the glass breaks at its weakest point. Some limited-range thermometers have an expansion chamber at the top of the scale but I cannot see one in either the Rondinax 35U or the Essex. Therefore, the tank should not be washed in water higher than the maximum temperature shown on the scale.
The instruction manuals say nothing about this problem. I suppose when they were written the ability to get hot water straight from the tap was very uncommon.
I have been pondering on the relationship between the inventors of Rondinax tanks, the manufacturers and those who sold them under their brand, namely Agfa, Leitz, Johnsons of Hendon and Neville Brown.
This post, in a way, extends the information shown in the separate Page (see Menu above) on Patent History.
On reading what I can about Michael Lesjak, I am coming to the tentative conclusion that neither he nor Wilhelm Kehr were employees of Agfa.
Let’s first consider Michael Lesjak. Apart from his 25 patents, for which Espacenet is invaluable, Google searches are not very fruitful. However, starting in 1920 he invented a new way of packaging photographic plates so that they did not become scratched whilst being changed. A number of international patents cover this invention and it is mentioned in a few photographic histories from continental Europe.
Here is the heading of the British patent and the start of the description.
Note he is described as Photographer.
In 1922, with Friedrich Egg, he invented a toy carousel, suggesting he was a private inventor rather than a company employee.
Before the invention of what became the Rondinax tanks, there are two German patents, again granted to Lesjak and Kehr, that describe a side-loading developing tank with a slit and sealing device. The applications were made in 1932 and the patents were granted in 1933.
I now wonder if those patents were the precursors of the patent granted to Optochrom (also from Augsburg) in 1936 from an application made in 1934. The principles are not dissimilar. Was there a close relationship between Lesjak, Kehr and Optochrom (by then manufacturing its glass filters)? All the parties were located in Augsburg. I would like to find out who the shareholders in Optchrom were.
In 1950, I can find mention of a Michael Lesjak of Augsburg being Secretary of a flying club set up as soon as the Allies permitted their formation in the aftermath of the Second World War.
By 1953, a patent granted shows that Michael Lesjak had died. Whether or not he had died by the time the patent application was made (late 1950) or amended (1951) I cannot tell.
Overall, my impression is that the intellectual property was licensed by Lesjak and Kehr (Kehr was involved throughout in the invention of daylight-loading tanks) to Agfa for the production of the Rondinax tanks before and after the war. Did they make separate licensing deals with Leitz (in association with Agfa)? How did Johnsons of Hendon and Neville Brown (NEBRO) obtain the rights to manufacture Essex and Kent tanks in Britain after the war? Was it by a direct deal with the inventors or were Agfa also involved since they may not have been in a position to export or even manufacture tanks at that stage? Agfa was certainly having its problems after the Second World War. It was a constituent company of I.G. Farben which was being broken up by the Allies because of its close involvement with the Nazi regime and the production of Zyklon B for killing millions of people in the extermination camps. The fate of Agfa was not finalised until 1952 (Opting for Oil: The Political Economy of Technological Change in the West German Industry, 1945-1961 by Raymond G Stokes, Cambridge University Press, 2006).
Further information would obviously be very welcome.