Leitz Agfa Rondinax 35 Daylight Film Developing Tank Review

Leitz Agfa Rondinax 35 Daylight Film Developing Tank Review

1800 1012 Nick Clayton

“Ok, got the film out.” the message read. What followed in the chat was a photograph showing the full length of a 36 exposure roll of film spiraling out of its canister in front of a flung-open camera back. This is but one of the adventures of teaching analog photography to high school students over chat during distance learning in a pandemic. In a sense, it’s not such a bad way to learn – mistakes are life’s best teacher. This particular student learned a lasting lesson about the light-sensitivity of film, and how to properly unload film from a camera.

In the year prior to this incident, I had arranged a field trip to Gallery 44 in downtown Toronto for my Photography Club students to participate in a darkroom workshop. The workshop was an absolute hit. That’s not to say it was without challenges, though. The best part of any darkroom experience is seeing your images appear on photo paper in the developer, but the printing portion of the workshop was cut short for some students who had spent a large portion of the workshop struggling to load their exposed film onto reels and into developing tanks in total darkness.

Despite the setbacks, the workshop was a great success with the kids, who couldn’t wait to get back into a darkroom. That warmed me to the idea of having a darkroom at the school, and I began to ask for donations and to scour the internet for the necessary equipment.

In the process of looking for Paterson developing tanks I had the good fortune to stumble across the Rondinax 35 Daylight Developing Tank. The discovery of a tank that could be used outside of a darkroom or changing bag triggered the memory of those students who blindly struggled to load their film into developing tanks in the dark, and I decided right there and then that the Rondinax Tank was an essential piece of kit.

What is the Rondinax 35 Daylight Developing Tank

The Rondinax 35 Daylight Developing Tank is a 35mm film development tank that can be loaded and used in the light. This means that no part of the developing process must occur in darkness, as is the case with most other types of development tank, like the typical Paterson tank that almost every new film shooter will use today. 

The Rondinax was made by Agfa, and at different times was branded and marketed under other names. The one I bought is the Leitz Agfa Rondinax 35. They also made 120 medium format Rondinax tanks, though these are harder to find and more expensive. 

The Rondinax shares features with both a camera and a record player. Like a camera, it is a light-tight box, but instead of a shutter and aperture for an opening, it has a port for chemicals. Like a record player, it spins a disc, in this case a developing reel.

Like a camera, it has a mechanism for loading film, but instead of film moving to a take-up spool, it is fed onto a developing reel. A clamp affixed to a rubber strap is attached to the trimmed film leader, with the other end of the strap attached to the axle of the developing reel. A spin of the exterior dial turns the reel to wind the strap around the axle, which pulls the film from the canister (at this point the lid goes on the tank to protect the emulsion from light). The film is fed through a mechanism that lightly squeezes the film edges before they are unfurled into the grooves of the reel, moving from the center of the reel to the edge. Pretty clever.

A modern version of the Rondinax has been manufactured by Italian film specialist Ars-Imago, called the Ars-Imago Lab-Box. This device is essentially a modern take on the Rondinax, and it works just as well. The price, $180 USD, is about double what we pay for a vintage Rondinax. Buyers will need to weigh the cost of new materials, total price, and the value of history, and determine for themselves which is the more appealing device. 

Using the Rondinax 35 Daylight Developing Tank

Sometimes if I’m feeling especially bold I will fully embrace the daylight developing tank by developing film with it outside on a sunny day, for no other reason than because I can. Even though the Rondinax may allow you to stay in the light while developing, the film is still in the dark, so there are some thoughtful features to provide you with feedback about what is happening inside the tank. First and foremost, the whole process should be butter smooth, and if it isn’t you know you’ve had a mis-feed and should start again.

A truly helpful feature is the exposure gauge on the side of the tank. As previously mentioned, the film feeds into the grooves of the reel from the center to the outer edge, and as it does the feeding mechanism slowly raises like the arm on a turntable moving through a record (in reverse). When it comes to rest, an attached metal arrow, which is visible on the exterior of the tank, will indicate 12, 24, or 36 exposure marking, depending on the size of the roll. Once confirmed, you use the internal guillotine-style blade to cut the end of the roll, freeing the film from the canister, allowing it to move completely onto the reel. You definitely do not want to make the cut before we’ve in fact reached the end of the roll, which is why this feature is nice to have.

There is a built-in thermometer for determining the temperature of your chemicals. Mine doesn’t work, as far as I know, and this may be a common problem. I check the temperature before processing so I can set my timer anyway, so it’s not a big deal.

The Rondinax uses less chemicals than a Paterson tank. That has a lot to do with the tank being smaller and only capable of processing one roll at a time, but also because that relatively small tank need only be filled halfway; the reel is rotated by turning the external dial attached to the axle of the reel, cycling the emulsion through the pool of chemical that rests in the lower half of the tank. In fact, if the tank is filled above the midline, it is prone to leaking through the hole that connects the axle to the dial.

The tradeoff for economy comes in the form of elbow grease, or more accurately, carpal tunnel syndrome; the developing process requires constant agitation in order to ensure even development of the film, which adds up to about ten minutes of spinning per roll of film.

If processing several rolls of 135, the Rondinax might not be the most efficient choice compared to a large Paterson tank. The level of tedium involved in spinning a dial for that duration alone would be considerable. This is likely the driving force behind the ingenious solution I have seen online of rigging a small battery motor with a belt drive to spin the exterior dial automatically on your behalf.

That said, I have put many rolls through mine spread out over the course of a year, and despite some minor mishaps such as leaks, misfeeds, and the cutting of some rolls a few frames early, the relative ease and convenience compared to fumbling in the dark has been a noticeable and welcome change.

All of this is not to say that the Rondinax negates the need to engage in the learning curve of using Paterson tanks. This process is second nature to many, and mastery is certainly attainable for anyone, with practice. The Rondinax Daylight Developing Tank however, does not have the same degree of difficulty right off the bat, and that makes it a good entry-level training tool. This device is also a potential cost-saver and waste reducer, as it requires less chemical. Where its true strength lies is in developing single rolls. In this case its convenience is hard to beat, and that makes it a useful addition to a darkroom.

Browse for a Rondinax Tank on eBay

Get the modern Ars-Imago Lab-Box from B&H Photo here


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Nick Clayton

Nick Clayton

Nick Clayton is an educator, musician, environmental advocate and photographer living in the Blue Mountains of Ontario, Canada with his wife and their three children. He can be found on Instagram & Twitter as @nicknaclayton

All stories by:Nick Clayton
17 comments
  • Thanks for the review, just wanted to mention an even more economical variation on the Rondinax called the Rondix, only uses 200ml of chemicals. Almost as efficient as a Jobo-ATL!

  • Avatar
    Andrew in Austin, Texas August 17, 2020 at 8:50 am

    That was an enjoyable read over a morning cup of coffee. More so, because I spent a decade as a high school physics teacher before returning to the ivory towers.

    I occasionally use a Rondinax with HC110, dilution B. With Rodinal – I wouldn’t dilute further than 1:40.

    On a technical note: To achieve a proper negative gamma of .65, the Rondinax user needs to reduce the published developing times by 15 to 20% to compensate for the continuous agitation of 1/2 rotation, @ 2 second intervals. Also, the developing time will need to be reduced further when the developer is above the recommended 20 degree Centigrade temperature. If not, the negs will be over developed. The latter is useful for doing a quick and dirty development without tempering the tank or chemistry in a room that is at 72 to 75 degrees Fahrenheit.

    Finally, do an internet search for “Malcolm Peaker Rondinax” – more than enough info will follow.

  • I hate to say this, but a major problem with film is the requirement for wet chemical developing. It seems to me that what would be ideal for film would be film that is permanently developed on exposure to light without any further necessary chemical alteration. Any ideas?

    • Well, I guess it’s quite difficult for the film to distinguish the first exposure to light (intentional) from subsequent exposures (for the purposes of viewing). But you are perhaps straying into the area of camera-less photography, such as blueprints or cyanotypes. With a cyanotype you put your treated paper in the sun, either with objects or a large negative on top of it. You expose it for a while, then just run it under the tap for a few minutes and dry. Voila, a lovely blue and white image!

      • Yes, you are right, the film emulsion would have to contain a material that is only initially sensitive to light and possess the ability to then become insensitive to light or at least much less sensitive to light. Perhaps a biological chemical like chlorophyll or hemoglobin or rhodopsin or some similar chemical that could be initially altered by light and then become relatively insensitive to light could be used? The concept is clear, but the accomplishment is probably quite difficult. Thanks for your comment and example of cyanotype. Alternative photographic processes are described in this article, https://petapixel.com/2017/03/31/8-beautiful-alternative-processes-photographers/.

    • How about an atom bomb light source and a brick wall for paper ?

  • “Sometimes if I’m feeling especially bold I will fully embrace the daylight developing tank by developing film with it outside on a sunny day” Great article, Nick. Just one word of warning… it’s best to load the film in a slightly subdues light area. I used to load mine in the laundry off the kitchen, with the door open and light streaming in. But sometimes when scanning the film I would notice occasional negatives getting marred by a small light mark. After much experimenting I worked out that light was reflecting upwards from the metal draining board and sufficient was coming up the guillotine slot, to cause a light leak at the points where I paused my wind-in! Now I take the tank into the kitchen away from the light for the wind-in/load process, and everything is fine.

    I also have a Lab-box with both the 135 and the 120 module. It requires more chems (300 vs 200 ml, because the chamber is big enough for the 120 film, I think). First time I tried it I used the optional handle (rather than the standard knob). But I found it quite awkward to wind as the handle is a bit low down and close to the table. I also thought there would be a tendency to turn the handle to the same point each time, which might lead to uneven development. With the knob, things go much more smoothly. It’s certainly good being able to dev my own 120.

    I use these because my right hand is a bit damaged from an accident years ago, and I think it would be nearly impossible for me to load a film onto a spool in the dark!

    • Thanks for the warning Chris, I do enjoy learning from other people’s experiences 🙂 That crank handle doesn’t seem like the best option, ergonomically, and I think you make a strong case for the knob. Sounds like you’re a great candidate for a motorized tank with your injury. The knob would connect nicely to a belt drive. I’m thinking the guts of an old record player might do the trick….

  • I learned on stainless steel reels and now that I have the hang of it, I wouldn’t trade it for anything. It took a bit of dedication but my tank hold four reels and it takes me about 15 minutes or so to load all four reels. A few gentle inversions and in the same time as one I have four rolls developed. I usually just fold the edge of the film to square it off and then wrap them onto the spool, the wrapping is very similar to what you described with this device from the center out, give it a try sometime

    • I started with the stainless steel reels as well. Nothing wrong with them! Whatever works best and is within each individual’s comfort zone.

  • 1) Yes, the Lab-Box is much more expensive than a 35mm Rondinax, but it’s less expensive than buying both 35mm and 120 Rondinaxes (Rondinae?)

    2) Also, the Lab-Box doesn’t leak around the agitation knob, because it’s sealed with a modern automotive-type lip seal. The Rondinax is sealed by wishful thinking, basically.

    3) I just made one of those motorized knob-turners and am crushed to hear I’m not the first person to think of it, but robotic knob-turning is pretty awesome. Mine required about $30 worth of hobby robotics parts, a strip of metal, and some zip ties, which is a small price to pay from freedom from the tedium of turning that dratted knob!

    • That is a very valid point to consider – if you are developing 120 & 135 film the Lab Box is more cost-effective. That is assuming that you could actually locate a Rondinax 120 in the first place.

      You should share your motor design online, I’m not aware that anyone has actually made a DIY post anywhere. I would certainly appreciate it!

  • My Rondinax doesn’t leak. Am I doing something wrong? 😊

    • Clive, you’re lucky! My Rondinax leaks… it doesn’t cause problems during normal development, as the chems are only just about up to the axis level anyway. It is a problem when I fill it up for the washing cycles…

    • You’re definitely missing out on the full experience 😂

  • I had a daylight loading tank made by Jobo which resembled a standard tank, but chunkier. It could handle only one 35mm roll at a time and required the tongue of the film to be left out of the canister when rewinding. The secret was a reel that loaded from the inside out. You would insert the film in the middle the reel and hook it unto the sprockets. The reel was placed in the tank and the water tight cover was installed leaving the center open where the film canister could still be seen. Then a light proof tube was inserted in the hole–it was open on one end, the other having a plastic plug. The tank was then light tight. You would manipulate the tube back and forth much like the motion used to load a standard plastic reel. The film would be pulled out of the canister and wind onto the reel until it could be pulled out no more. Then the genius part: the open end of the tube had a serrated end. Once all the film had been taken up by the reel, you would turn the plastic tube past a detent which would cause it to descend into the hole and close off the center of the tube where the canister remained. The serrated end would cut the film and finally close to the point where the tank was light tight but the chemicals could still make there way into the tank through baffles. The plug at the other end of the tube was driven upwards and out by the canister. You inverted the tank and the empty canister fell out and you were ready to develop!

    • Avatar
      Andrew in Austin, Texas August 30, 2020 at 7:42 am

      That would be the Jobo 2400. I still have one and it is my go to tank for semi-stand development of a single roll of 35mm film using.

      My example of the Jobo, is well worn and no longer spits out the film canister as it supposed to. It uses a bit more developer and fixer than a regular tank, 450ml in fact – which is helpful when doing stand or sem-stand development.

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Nick Clayton

Nick Clayton

Nick Clayton is an educator, musician, environmental advocate and photographer living in the Blue Mountains of Ontario, Canada with his wife and their three children. He can be found on Instagram & Twitter as @nicknaclayton

All stories by:Nick Clayton