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aapo lettinen

Leicina 8 Crystal Sync Update

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I started to modify my new Leicina S to real Crystal Sync as soon as it arrived today.

There seems to be a demand for sync sound Dual 8 cameras so the update, when ready, will become available for order one way or another. I will do a lot of prototyping and testing in the following months and will post the results here 🙂

The first stage was to disassemble the motor side of the camera to see what the possibilities are to attach a speed sensor to the original motor and how much there will be space available for the circuit boards. I also calculated the reference frequencies needed and did some drafting. 

The next stage will be to manufacture a custom speed sensor assembly for the motor and then hook it up to my existing Crystal motor controller prototype and start to run sync tests. 

I can already say at this stage that this WILL work correctly. Release schedule is TBA at the moment but I would say "pretty soon" at this stage because I already know how to do this conversion and have most of the electronics design ready  🙂

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Edited by aapo lettinen
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7 hours ago, Simon Wyss said:

I’d like to make a suggestion, that you change to 9 V batteries.

I'll test how that would work!

I am probably testing some type rechargeable Li-Ion batteries as well. The main goal is to have a small battery so that it does not take much space and leaves more room for the control boards.

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Today I made a very basic magnetic encoder disc for the first tests I am going to run soon. I had these axle fittings from another project so was fastest this way... I just put some neodymium magnets inside the bolt holes and sealed them with tape after that. This adapter is made for slightly larger axle but the fitting works OK for the first tests after I added some tape on the motor axle 😛 

I am going to design a better encoder system later but this is great for tests and demonstration purposes. I am going to use self made Hall sensor circuit for reading the magnetic field changes which are used for generating the speed measurement signal after treated in the self made preamplifier. 

Everything extra is stripped from the camera body so that I can get good access to the motor. Easier to work that way. I am probably going to keep the original battery voltage meter so it can stay for now 🙂 

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I purchased two extra Leicina S cameras as well to get more lenses for my own use and to be able to disassemble one completely to reveal how the exposure control could be connected to the new electronics boards I'm going to make. Will also get some spare parts that way :)  I am going to run some Crystal Sync tests this weekend if I have time. As said I already know it is going to work (my sync system works and the motor itself works and the encoder works as well. so all the components of the system work correctly and I just need to connect them together, do some basic adjustments and shoot a video out of it :D  

Then I can start designing the final circuits and the circuit boards. The exposure system needs to be figured out first so I need to disassemble one of the extra cameras to see how to control it efficiently. If there is a possibility for it, I will maybe try to replace the exposure meter battery with an internal voltage regulator which takes power from the same battery than the rest of the electronics. So it is some prototyping now and then lots of circuit design :)

 

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I was so curious about the Leicina's auto exposure system that I already opened the front part of the camera to check it out. It needs a little bit more work to get it working it seems and there will be two different options how the exposure system of the camera can be modified: 

A.  Two extra wires are attached inside the camera body to run stabilised power for the light meter. So the additional light meter battery is not needed anymore at all ( the light meter battery compartment is left original looking so that the outer body of the camera is not altered. Automatic exposure works like before. No manual exposure. Probably no additional calibration made to the exposure system though I will adjust the supply voltage of the light meter so that it is as close as possible to the target to get proper readings. This light meter power replacement feature will be developed in any case and will be attached in the cameras which have the crystal sync update.

 

B. Light meter battery replaced with internal wires so that you don't need separate light meter battery just like in the update A. But a Manual Exposure Dial is manufactured and attached to get full manual exposure approximately calibrated in T stops ( I will work on this only if it gains enough interest. It needs lots of testing and calibrating, film tests and some machining job done. Price will be thus also higher and this will thus be an additional feature in any case. So let me know if you are interested in this manual exposure feature. Otherwise this feature will be delayed a lot or not developed at all.)  . With this update,  Automatic Exposure is limited or not possible at all (will know if there is enough interest on this feature so that I can start working on it) .

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Feature list of the camera update I am currently working on: 

- all features powered by one battery. No separate light meter battery needed 

- similar exposure system than the original camera has (let me know if you want full manual exposure. It is possible but it is lots more work and I need to know if it's needed or not or otherwise I will not work on the manual exposure feature for now) 

- battery options TBA. I will probably add some type of voltage regulation so that one can use a range of different batteries from 6 or 7 v upwards. I would like this to work on LP-E6 batteries for my own use so I will most likely work on that option among others. I will test the 9v batteries as well how they would work with the camera mod.

- FRAME RATES!  I will add at least 16fps, 24fps and 25fps for sync sound shooting. All very accurate crystal speeds. But does someone need 18fps? let me know at early stage because it will change the circuit boards and I will need to know early on.  

I am unsure if the camera body can handle more than 30fps. maybe I could test it because I have a additional camera body which is just for spare parts and can be sacrificed. Not promising anything though at this stage. 

- Start - Stop button on the side of the camera so that the handle does not need to be used for start and stop of filming. Also easier to start the camera on tripod. 

- Speed selector on the side of the camera. I have to check what would be most convenient. Simon originally proposed that the outer body of the camera should not be altered to keep the classic original look but I will try to make all the Crystal speeds internal and easily selectable so the selector is necessary to install. 

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Very early to ask but how many persons would be interested in this Leicina S camera update with that feature list? 

The Leicina seems to be very good camera so after the update it will be really useful for indie films, music videos and similar type of material. There is of course lots of work to do these updates and the camera needs to be serviced as well to be in good mechanical condition (Simon can arrange CLA for these Leicinas easily) . But it will be a real workhorse after these electronics updates and CLA. So it will be absolutely worth it 🙂 

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https://www.filmvorfuehrer.de/topic/31948-die-leicina-ist-60/

First publication of my article, a translation is being prepared.

It’s going to be the ONLY automatic camera with crystal control to the motor for Double-Eight film. A Paillard-Bolex H-8-4 with the ESM offers crystal speed accuracy, too, but is way bigger, heavier, and more expensive.

The Leicina 8 S has a low optical axis, a straight-pull claw, a ground glass can easily be added to the finder for critical focusing, and the built in 15 mm lens is very good.

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I made a "proof of concept" type of test today and ran the camera on crystal sync with all the basic components in place. It works correctly but my camera is not in very good mechanical condition and proper overhaul would greatly enhance speed stability. 

https://www.youtube.com/watch?v=Y0cEqkdUnaQ

But like I said, it works. This is not the final system in any way and I am using different circuit design for the final one. I just wanted to show what I am doing to the camera right now and how I am testing stuff with it. The commentary is pretty interesting if anyone is interested in how these systems actually do the speed stabilization. Check out my other crystal sync test videos as well :) 

Btw I secured some basic Leicina S kits from eBay for my tests. But I have enough of these cameras to build one or two final systems out of them and Simon can make proper overhaul to them to restore them in the best possible condition. If anyone is interested in this type of option, let us know :)   

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