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Making new Crystal Sync electronics for CP16R


aapo lettinen
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Aapo.

How difficult would it be to design a simple single-speed crystal-controller for the CP16R with the shutter park function. Multiple speeds are nice but maybe not necessary. Offspeed work is easily done on a Bolex. High speed shooting for slow motion is more conveniently doable with digital cinema and at less media storage cost than 16mm film. 

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Aapo.

Regarding a lens for a video split, if your C-Mount camera has a 2/3" sensor, you might be able to use Fujian C-Mount lenses with CS to C-Mount adaptor rings to macrofocus the lenses. The rings are 5mm thick from memory. The Fujian lenses are available as 25mm, 35mm and 50mm focal lengths. I was examining this at one time. My notion was to cut an approxiately 5mm thick piece of aluminium in the shape of the little hatch which closed the hole for the video split, mount it in a 4 jaw chuck on a lathe then machine the thickness down to leave a hollow shoulder to cut a thread onto for the filter thread of the lens as a means to mount it then use the lens to support the camera. 

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=fujian+C-mount+lens&_sacat=0&LH_TitleDesc=0&_odkw=Fujian+50mm+c-Mount+lens&_osacat=0

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1 hour ago, Robert Hart said:

Aapo.

How difficult would it be to design a simple single-speed crystal-controller for the CP16R with the shutter park function. Multiple speeds are nice but maybe not necessary. Offspeed work is easily done on a Bolex. High speed shooting for slow motion is more conveniently doable with digital cinema and at less media storage cost than 16mm film. 

I am using a self designed simple prototype board for my own tests which is single speed 24fps and does not have shutter park or film counter etc. Plus it does not have soft start or anything. If installing this type of controller to a external box so that the board does not have to be redesigned to fit inside the camera, then I would already have a single-speed system available. 

The reason I would want the final system to have more features is because it is time consuming to take out the old electronics and design new boards which fit inside the camera. everything has to be tested in the end as well so it is lots of work to convert this type of camera and thus it would be nice to have more features in the end than a very basic controller I currently use for the tests.

the external box single speed conversion would probably cost something around 500 usd + shipping and the planned final system with 10 to 12 internal speeds and all the shutter parking and film counter etc. features would be around 1000 or 1200 usd + shipping so to me it makes more sense to wait for the final version

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Thanks for sharing all your progress Aapo, nice to read this thread. I'm also interested in making a tap for it.

Last night i was finally able to pop-open the video assist cover and peek into it. Why is the image coming off the prism orange? Image is correct in viewfinder but wondering why it's orange when looking down in the tap hole.

I see that it is orange in your pictures as well.

 

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14 hours ago, Robino Jones said:

Thanks for sharing all your progress Aapo, nice to read this thread. I'm also interested in making a tap for it.

Last night i was finally able to pop-open the video assist cover and peek into it. Why is the image coming off the prism orange? Image is correct in viewfinder but wondering why it's orange when looking down in the tap hole.

I see that it is orange in your pictures as well.

 

I think the orange is due to the viewfinder prism's coating affecting the transmission of light. I don't know if the original video beamsplitter has any colour shift but the normal prism (like I seem to have in my camera) is likely not meant for video tap use and thus it just has the regular (aluminium?) partial coating which affects colours when shooting through it 

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9 hours ago, aapo lettinen said:

I think the orange is due to the viewfinder prism's coating affecting the transmission of light. I don't know if the original video beamsplitter has any colour shift but the normal prism (like I seem to have in my camera) is likely not meant for video tap use and thus it just has the regular (aluminium?) partial coating which affects colours when shooting through it 

I asked Ken Hale from Whitehouse and he said: "That is an infrared mirror, it only lets the black and white light through."

So it maybe best to use a monochrome camera?  

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13 minutes ago, Robino Jones said:

I asked Ken Hale from Whitehouse and he said: "That is an infrared mirror, it only lets the black and white light through."

So it maybe best to use a monochrome camera?  

it seems possible because the transmission is so poor on visible light. It is OK if the pickup camera is sensitive enough but I am planning on shooting mostly 100 iso films to be able to use the tap better

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  • 5 months later...

I am writing new crystal sync algorithm for the CP16R which is why it is taking a bit longer than expected to finish the modification. The system needs a limited amount of machine learning functions to perform correctly so it is much more advanced than my original crystal sync code and thus it is more time consuming to finish and test it too.

I have my original CP16R camera body and now got another similar cp16r which is in worse aesthetic condition (soundproofing materials missing from inside, the external paint in bad condition) . Having two camera bodies makes the modification easier and faster because it is easy to test stuff with lower risks. It should take about 6 months to finish the modification but will post results as soon as I get new tests done with the prototypes. I will sell one of the camera bodies after the modification is finished because only need one for my own use and would want to give someone else the change to use the spare camera for real work instead of keeping it in storage 🙂  

the final plan is 10 internal Crystal speeds and internal variable speed function for manual speed ramps. External input for additional speeds if needed. Film end warnings just like in the original camera but possibility to select other film amounts than 200ft and 400ft. The shutter park function if I get it working reliably.  Some kind of display may be possible but will test it to see how practical it would be and if it can be fitted nicely into the camera body. The speed selecting is done by using a rotary switch (much more practical than a display based user interface) so the possible display would only be used for film counters and battery voltage meters. 

I have already finished the electronics design and will concentrate on the software and mechanics now. Have run tests with my single speed crystal sync board but don't want to post any images of that design so will wait until getting the actual 10 speed design running before posting any videos 🙂 

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14 hours ago, aapo lettinen said:

I am writing new crystal sync algorithm for the CP16R which is why it is taking a bit longer than expected to finish the modification. The system needs a limited amount of machine learning functions to perform correctly so it is much more advanced than my original crystal sync code and thus it is more time consuming to finish and test it too.

I have my original CP16R camera body and now got another similar cp16r which is in worse aesthetic condition (soundproofing materials missing from inside, the external paint in bad condition) . Having two camera bodies makes the modification easier and faster because it is easy to test stuff with lower risks. It should take about 6 months to finish the modification but will post results as soon as I get new tests done with the prototypes. I will sell one of the camera bodies after the modification is finished because only need one for my own use and would want to give someone else the change to use the spare camera for real work instead of keeping it in storage 🙂  

the final plan is 10 internal Crystal speeds and internal variable speed function for manual speed ramps. External input for additional speeds if needed. Film end warnings just like in the original camera but possibility to select other film amounts than 200ft and 400ft. The shutter park function if I get it working reliably.  Some kind of display may be possible but will test it to see how practical it would be and if it can be fitted nicely into the camera body. The speed selecting is done by using a rotary switch (much more practical than a display based user interface) so the possible display would only be used for film counters and battery voltage meters. 

I have already finished the electronics design and will concentrate on the software and mechanics now. Have run tests with my single speed crystal sync board but don't want to post any images of that design so will wait until getting the actual 10 speed design running before posting any videos 🙂 

Maybe I missed this in scanning the pages of info. in this thread but are you using Arduino or some variation of it? I am into  uController programming and had thought about using it to do something like this but was curious what a fellow tinkerer thinks of the prospect?

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1 hour ago, Matthew W. Phillips said:

Maybe I missed this in scanning the pages of info. in this thread but are you using Arduino or some variation of it? I am into  uController programming and had thought about using it to do something like this but was curious what a fellow tinkerer thinks of the prospect?

I am using Atmega and Attiny microcontrollers at the moment but I am designing the circuit boards by myself and just bulk purchasing the chips from 30 to 100 at a time, then programming them and soldering them along with the other necessary components to my self designed boards.

Typically they look like something like this in the device: 

51738320567_619b587c16_b.jpg

 I have some Arduinos for testing the early software versions for user interfaces etc just because they have the built in usb connectivity and voltage regulators so that I can save time for not needing to hook up a separate ISP to them when making hundreds of small changes and testing what the end result was (I wrote for example the display functions on my Konvas 15epss Crystal Controller on Arduino IDE to make it faster and easier for me to modify it quickly on the fly when prototyping) but I don't use any Arduinos or other factory made boards for final devices as I am designing the final circuit boards completely by myself, sending the cad files to a factory and getting the board blanks back which I solder the components to and do the flux removal etc finishing, testing and QC before installing them to the devices . 

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34 minutes ago, aapo lettinen said:

I am using Atmega and Attiny microcontrollers at the moment but I am designing the circuit boards by myself and just bulk purchasing the chips from 30 to 100 at a time, then programming them and soldering them along with the other necessary components to my self designed boards.

Typically they look like something like this in the device: 

51738320567_619b587c16_b.jpg

 I have some Arduinos for testing the early software versions for user interfaces etc just because they have the built in usb connectivity and voltage regulators so that I can save time for not needing to hook up a separate ISP to them when making hundreds of small changes and testing what the end result was (I wrote for example the display functions on my Konvas 15epss Crystal Controller on Arduino IDE to make it faster and easier for me to modify it quickly on the fly when prototyping) but I don't use any Arduinos or other factory made boards for final devices as I am designing the final circuit boards completely by myself, sending the cad files to a factory and getting the board blanks back which I solder the components to and do the flux removal etc finishing, testing and QC before installing them to the devices . 

Fair enough. I suppose I misspoke. I meant "are you designing based on an Arduino-style workflow". I figured you would need to still make custom PCB. What I meant is are you following the Arduino style (having your custom PCB have the VR with smoothing caps, the ATMega chip, the 16 MHz crystal, etc.)

Good luck. I watched your videos on YouTube and you should really do VO work because your timber is incredible.

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19 minutes ago, aapo lettinen said:

I am using Atmega and Attiny microcontrollers at the moment but I am designing the circuit boards by myself and just bulk purchasing the chips from 30 to 100 at a time, then programming them and soldering them along with the other necessary components to my self designed boards.

Typically they look like something like this in the device: 

51738320567_619b587c16_b.jpg

 I have some Arduinos for testing the early software versions for user interfaces etc just because they have the built in usb connectivity and voltage regulators so that I can save time for not needing to hook up a separate ISP to them when making hundreds of small changes and testing what the end result was (I wrote for example the display functions on my Konvas 15epss Crystal Controller on Arduino IDE to make it faster and easier for me to modify it quickly on the fly when prototyping) but I don't use any Arduinos or other factory made boards for final devices as I am designing the final circuit boards completely by myself, sending the cad files to a factory and getting the board blanks back which I solder the components to and do the flux removal etc finishing, testing and QC before installing them to the devices . 

programming a bare Atmega328 microcontroller on a breadboard with a simple ISP.  this is why I like to use Arduino Uno for early software versions of Atmega328 code: less wires and hassle if needing to change the code hundreds of times during the day. 

50690535151_d25c84576f_b.jpg

 

Loading the final software version into the Atmega328 which I installed to my self designed circuit board. This is one of the intermediate prototypes for the Konvas controller and not the final device: 

50990520952_78d7937044_b.jpg

 

Calibrating one of the intermediate prototypes using an oscilloscope: 

50990520902_a2892dc57c_b.jpg

 

It is tons of more stuff than just using an Arduino for controlling a camera some simple way. In most cases one needs to specifically design the boards from ground up for the exact camera model and motor you need them for. The same goes with the software... nothing readily available can be used for the job, not even as a reference when designing stuff.

Based on my experiences, I can only recommend purchasing a factory made PID controller with a brushless motor if wanting to modify a camera by yourself... or to order a finished solution from someone specialised in crystal sync systems if not wanting to use a factory made pid controller for your camera.  

I am personally only working on these crystal controller systems because I have too many broken cameras in storage and I am frustrated not being able to use them because cannot afford to send a dozen cameras for crystal sync conversion to someone else. Developing these systems is expensive too though which is why I am trying to sell at least couple of them to get even some of the money back which I invested in components and tools to be able to work on them in the first place 😬   

 

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2 minutes ago, aapo lettinen said:

programming a bare Atmega328 microcontroller on a breadboard with a simple ISP.  this is why I like to use Arduino Uno for early software versions of Atmega328 code: less wires and hassle if needing to change the code hundreds of times during the day. 

50690535151_d25c84576f_b.jpg

 

Loading the final software version into the Atmega328 which I installed to my self designed circuit board. This is one of the intermediate prototypes for the Konvas controller and not the final device: 

50990520952_78d7937044_b.jpg

 

Calibrating one of the intermediate prototypes using an oscilloscope: 

50990520902_a2892dc57c_b.jpg

 

It is tons of more stuff than just using an Arduino for controlling a camera some simple way. In most cases one needs to specifically design the boards from ground up for the exact camera model and motor you need them for. The same goes with the software... nothing readily available can be used for the job, not even as a reference when designing stuff.

I do not understand what you mean "some simple way". If you are controlling a motor, you need to work out the timing and distance. It isn't "simple" but it isnt particularly difficult either if one knows how to code. I would think the most difficult part is getting the board the correct size/shape to fit in the camera properly and retrofitting any new components.

This isnt meant to be disrespectful but there are plenty of tutorials on robotics/proper motor control out there to make that part of it relatively simple.

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3 minutes ago, Matthew W. Phillips said:

I do not understand what you mean "some simple way". If you are controlling a motor, you need to work out the timing and distance. It isn't "simple" but it isnt particularly difficult either if one knows how to code. I would think the most difficult part is getting the board the correct size/shape to fit in the camera properly and retrofitting any new components.

This isnt meant to be disrespectful but there are plenty of tutorials on robotics/proper motor control out there to make that part of it relatively simple.

controlling a motor "some simple way" means for example using a Arduino to measure the frequency from the motor's encoder (the running speed of the motor) in Hz /rpm/fps/whatever number and then comparing this to a reference number (the motor running for example 24.85fps and the reference number aka the target being 24.00fps) to work out how much the motor's speed is off and then adjust the motor power back and forth until the motor rpm matches as closely to the target number as possible.  for example using the simple pulseIn function in Arduino to measure the pulse duration from the encoder and work out the motor speed from that number.

This is the "speed measuring" method of controlling the motor but it has nothing to do with crystal sync systems and it is hundreds to thousands of times less accurate than real crystal sync system. the real crystal sync systems are not used for much anything other than movie cameras so there is nothing readily made available and thus they need to be made out of scratch every time which is very time consuming and challenging

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2 minutes ago, aapo lettinen said:

controlling a motor "some simple way" means for example using a Arduino to measure the frequency from the motor's encoder (the running speed of the motor) in Hz /rpm/fps/whatever number and then comparing this to a reference number (the motor running for example 24.85fps and the reference number aka the target being 24.00fps) to work out how much the motor's speed is off and then adjust the motor power back and forth until the motor rpm matches as closely to the target number as possible.  for example using the simple pulseIn function in Arduino to measure the pulse duration from the encoder and work out the motor speed from that number.

This is the "speed measuring" method of controlling the motor but it has nothing to do with crystal sync systems and it is hundreds to thousands of times less accurate than real crystal sync system. the real crystal sync systems are not used for much anything other than movie cameras so there is nothing readily made available and thus they need to be made out of scratch every time which is very time consuming and challenging

Wait...let me get this straight...are you implying that the ATMega sync is not accurate? This is news to me since these are the same types of chips that are used in time intensive applications that need more precision than ~41.67 milliseconds.

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2 minutes ago, Matthew W. Phillips said:

Wait...let me get this straight...are you implying that the ATMega sync is not accurate? This is news to me since these are the same types of chips that are used in time intensive applications that need more precision than ~41.67 milliseconds.

I created a laser tag system from an ATMega setup and it would send IR pulses into the uSecond teritory with incredible precision. I could send data packets with pulses faster than a single frame in a 24 fps camera.

Edited by Matthew W. Phillips
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the issue is getting the actual motor running speed to be so stable that it is close to the accuracy of the crystal itself or at least in the about 100ppm range if possible. the Atmega chips are fine, it is just that one can't match the motor speed to a target with that kind of accuracy with speed measuring methods (speed measuring methods are not accurate enough) and that is why speed measuring methods are not used for crystal sync systems

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2 minutes ago, aapo lettinen said:

the issue is getting the actual motor running speed to be so stable that it is close to the accuracy of the crystal itself or at least in the about 100ppm range if possible. the Atmega chips are fine, it is just that one can't match the motor speed to a target with that kind of accuracy with speed measuring methods (speed measuring methods are not accurate enough) and that is why speed measuring methods are not used for crystal sync systems

Does the CP16r use a regular DC motor or a stepper motor?

Edited by Matthew W. Phillips
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41 minutes ago, Matthew W. Phillips said:

I meant "are you designing based on an Arduino-style workflow". I figured you would need to still make custom PCB. What I meant is are you following the Arduino style (having your custom PCB have the VR with smoothing caps, the ATMega chip, the 16 MHz crystal, etc.)

voltage regulators, the smoothing caps and crystal are in most cases always needed even only running a display so one has to include them in all designs. But stuff like connectors can be customised easily if making your own boards and unnecessary stuff like usb connector, led lights, reset button etc. don't need to be included which gives lots of freedom when designing the system

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2 minutes ago, Matthew W. Phillips said:

Does the CP16r use a regular DC motor or a stepper motor?

all crystal sync systems use regular dc motors because steppers are too noisy for any motion picture use except for time lapse sequences. All the old crystal cameras use brushed motors and some of the newer designs use brushless motors. there is pros and cons on both of the motor types (brushless are not always the best choice for all the applications and are not always the easiest ones to control either) . I have concentrated in brushed motors because there is not enough brushless options available to make them a viable option for every use and often the camera's original brushed motor is totally fine and can be used as is

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1 minute ago, aapo lettinen said:

all crystal sync systems use regular dc motors because steppers are too noisy for any motion picture use except for time lapse sequences.

Maybe that is true in the old days but that is not true at all today. Thanks for answering my question however. I now understand the problem with getting the precision. A stepper motor would make short work of the precision issue but it might not work in the camera body. Now you have me wanting to play with motors to see what possibilities there are.

Also, sound isolation has came a long way since what was present in those old cameras. Might be interesting to see how much more the sound can be baffled with an eye toward that front.

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  • 3 weeks later...

I AM MAKING A SIMPLE 12-SPEED EXTERNAL BOX CRYSTAL CONTROLLER FOR THE CP16R in January to test various camera functions for the much more complex final crystal update which has all the bells and whistles like displays and so on.

This is a great opportunity for budget shooters to get their non-working CP16R updated to working crystal sync because the final update with a display costs from 1000usd to 1200usd + shipping but I can do these simple external box modifications for as little as 500 USD + shipping.  

When I have the final more advanced controller available, this simple external box modification is not offered anymore. I am planning only doing a single batch of these in February to get more cameras circulating and to get enough resources to finish the more advanced final update sometime this year. It would be optimal to get about 4 cameras for this simple modification in February.

Specs of the simple modification with a external crystal control box for camera speed adjustment:

- 12 internal speeds, all crystal:

3fps  (works as a inching speed)

8fps

12fps

16fps

20fps

22.01fps

23.976fps

24.00fps

25fps

29.976fps

33.333fps

40fps

- Variable non-crystal speed from 5fps to 40fps

- Start-stop button on the control box and possibility to use external wired start button which is included

- No shutter parking but you can use the 3fps inching speed to run the camera forward in steps to reach correct mirror position

- No indicator lights in the viewfinder

- I will test an audible film end warning when getting the prototype working this month. the film end warning may or may not be included depending on how it works in the prototype

- Power input via 3-pin xlr.  I can wire the original onboard battery plate to work with the system as well so that the camera has dual power inputs (it automatically takes the power from the highest voltage source available whether it being the XLR or the original onboard battery

- the control box is small and lightweight enough to be mounted on top of the camera using a normal monitor arm

------------

PLEASE LET ME KNOW IN JANUARY IF YOU ARE INTERESTED ORDERING THIS MODIFICATION FOR YOUR CAMERA. I will most likely only do a single small batch of these and it is much easier to arrange everything and easier and quicker to modify the cameras if I'll know beforehand how many orders there will be in total.

Ordering this simpler more affordable modifications supports me finishing the final update much sooner and helps making the final update better. This simpler external crystal box uses some of the modules from my Konvas 15epss Crystal Controller which is why it is much faster and easier for me to make them because I already have most of the parts available and I mostly need to charge for the actual work for modifying the camera body itself.

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I may have overlooked a mention of this but does it have any sort of closing-contact output or open-collector output for automatically starting an external audio recorder?

Probably a bit late to mention now!

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Posted (edited)
3 hours ago, Phil Rhodes said:

I may have overlooked a mention of this but does it have any sort of closing-contact output or open-collector output for automatically starting an external audio recorder?

Probably a bit late to mention now!

the original boards don't have one but it would be possible to wire an additional open collector output from the start-stop switch. Or it would be possible to make a small additional circuit board which has a programmable detector which gives a signal either when the camera motor starts or when it has reached the target speed.

The start-stop switch uses a +5V floating pin which is shorted to ground when the button is pressed. the control box will have a simple 2-wire output for external start-stop button and it would be possible to get the button press signal from that same wire to control external devices with the same button if needed, that would be a simple user modification possible to do at home because one would only need to hack the external button cable and connect to the floating wire to get a signal from there. The additional speed detector board would cost some extra but the open collector output and button wire hacks would be free because they are very easy to do.

Edited by aapo lettinen
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