Projector conversion for Telecine?

[David Runier]

I am about to embark on plans for digitising all my Std 8 and Super 8 movies (and 9.5mm sometime in the future) using a converted projector and - probably - a Raspberry Pi and R/Pi camera, although initially I shall use a mirrorless camera for testing and proofing the set-up.
I am looking to buy a suitable projector for this purpose and a second-hand Eumig Mark 8 is a potential choice, both because it looks to be well made and reasonably heavy, and uses dedicated sprocket feed rollers and gates for the two 8mm guages, which I suspect are a better bet than an auto switching system. Also, looking on eBay, and bought from a private source, they don't appear to be terribly expensive.
Has anyone adapted one of these or a similar model and know of any potential pitfalls specific to Eumig projectors, or can recommend another make? I anticipate the motor speed will need to be adjusted to give between 1-4fps and there needs to be enough room to fit an optiswitch somewhere to trigger the camera.
Does the original Eumig speed control go down to that level without modification? Is the motor a DC unit? (the older P8 model looks like it uses an adjustable coil resistor for speed control). Can the speed be regulated on this model using an AC speed control unit connected between the power socket and the projector if this proves to be necessary?
I live in Cyprus and the projector will have to be shipped out here, so don't want to discover unexpected problems after it arrives so any early information, suggestions, or warnings would be very welcome.

Thanks
David

[Brian Fretwell]

I think that all Eumig projectors from around that time use mains voltage synchronous A.C. motors (using the windings as an intergal part of the lamp transformer) so the slow speed could be a problem.

[Stan Jelavic]

Not familiar with these projector models but as Brian said it, ac synchronous motors speed is determined by the line frequency and are not good for variable speed operation. But wanted to comment on RPI cameras. I played with several models and one of the main issues is the mismatch between the lens and sensor CRA.
https://www.ccdcmoslens.com/pink-glo...ra-sensor-cra/
I struggled with this issue and even did the compensation tables. They do help but still not perfect. Some glow still stays present.
The best bet is to verify the CRA for both the sensor and the lens and make sure they are close.
Also storing of the streamed video may be an issue because of RPI performance depending on the video resolution. I have been looking at the two camera models as we speak:
https://www.amazon.com/gp/product/B07ZS9KSZR/ref
https://www.amazon.com/gp/product/B08D3DRRYX
These are HDR capable.
Another 13MP model has very pronounced pink glow when used with the 16mm lens and I don't recommend it:
https://www.amazon.com/gp/product/B08D3KRVLQ/

[David Runier]

Thanks for the comments, that is exactly the type of information I need ahead of making decisions. The synchronous motor might rule out using Eumig, but they have a 16fps/24fps switch - is this a change of gearing or is there some circutry that does the job? In all other respects they seem to have the features I'm looking for.
I had not thought of the CRA being a potential problem. Using a M4/3 camera during the set-up period with the lens extended well away from the sensor, the light rays will be close to parallel. But when I later switch to a much smaller sensor I can see this needs to be taken into account as the rays will hit the sensor lenses at a greater angle. Thanks for that warning. I'd be very interested in hearing any further thoughts on this subject.
Any suggestions on suitable alternatives to the Eumig projector range anyone?

[Stan Jelavic]

I used Chinon Whisper several years back. It has a 36V DC motor and a rheostat control with limited range due to low torque at low voltage. They are still available at pretty low price. But there are many more out there with DC motors. I will send out RPI test results within next few days.

[Nantawat Kittiwarakul]

I currently use Fujicascope dual 8 projector (forgot the model no., but the most basic ones) with variable speed dc motor. It is intended to be run at something around 24-30vdc, but I found out that it still works (barely) at as low as 12vdc and giving the resultant speed around 5 fps - just slow enough for my setup.

So yes I recommend looking for variable speed projector with dc-drive motor. That should considerably simplify your work of course.

[David Runier]

I have been reading a lot more, and looking on eBay, and the Eumig Mark 8 (or M-DL) is still the number one choice, despite the fact they use a frequency controlled motor. I haven't been able to find any mention of the wattage of this motor but there are frequency speed controllers on eBay for about £20, so I may still go in this direction. Eumig projectors were very popular in Europe so there are plenty of second-hand ones available in very good condition, and they were well engineered.
What (free?) software do you use to clean up the images after transfer? If I remove the projector lens and copy frame-by-frame with a macro lens, the image is upside down and laterally reversed so there must be something that will correct this and hopefuly allow me to adjust exposure on the copy for overly dark or light scenes, and what about colour correction for old faded colour film?
I am now considering using my existing M4/3 camera with a macro lens and tripping the electronic shutter using an optiswitch and a relay, to try and keep things as simple and straight forward as possible, and with the least amount of outlay at this stage. Also easy to set white ballance for the replacement LED light source, but I haven't given up on the RPI approach for the longer term.

[Stan Jelavic]

AR0230 usb version looks pretty reasonable and has just a slight brightness variation between the center and outer edges that is only noticeable if the image is pure white. Tried the RPI AR0230 but the driver does not support the latest OS version. Will get in touch with Arducam.

[David Runier]

Stan
Quality looks good. I have run into a slight problem insofar as neither Amazon UK nor the UK or German distributors for Arducam list the AR0230. They tend to use their own product coding so I shall have to investigate further to see what is available here (USPS rates to Europe are horrendous, so buying from the US is a non-starter), but initial findings suggest (not surprisingly) that the emphasis is on RPi gear on this side of the pond.
You mention using a 16mm lens which would be semi-telephoto in terms of the 1/2.7" sensor, (equivalent to 98.4mm on a full-frame 35mm camera) and with the lens extended for macro the light rays are going to be close to parallel, so any shading is probably inherent to the sensor, which may account for the variation centre to edges, and something we have to live with.
If you are copying the 8mm frame 1:1 on the sensor then the lens should be about 32mm from the actual film surface and if that is the case does the empty tubular housing for the original projector lens permit your 16mm lens to fit inside?
David

[Stan Jelavic]

Hi David. I tested the camera with the 12mm lens as well and the shading seems to be better. Will double check.
This was used with the Wolverine/Hawkeye setup and the lenses are small M12 type. If you are using it with the projector you could consider different lens formats but that could impact the shading performance. With the 16mm lens the camera would have to be 64mm from the the film which may not be possible. I believe I have some longer FL lenses kicking around and can try testing the board with them at 1:1 mag ratio.

[David Runier]

Well, for good or bad I have bought an Eumig Mark 8 projector and ordered the advertised frequency adjustable speed controller. They will both take about 6 weeks to arrive so there is nothing more I can do until then, except gather more knowledge. Whatever system of tranfer I finally adopt, I am going to need software and would appreciate as many recommendations from members using current free or shareware that provides the necessary means of flipping the image vertically and laterally, allows edits, adding titles, grading and anything else that is necessary to get the best final result from the transfer.
Thanks to everyone for their comments so far
David

[Stan Jelavic]

I use DaVinci Resolve free sw. Tons of instructions available on y..tube.
https://www.blackmagicdesign.com/pro...avinciresolve/

Avi synth_VirtualDub2+VideFred:
http://avisynth.nl/index.php/Main_Page
https://sourceforge.net/projects/vdfiltermod/
https://forum.doom9.org/showthread.php?t=144271


Film9
https://contact41766.wixsite.com/film9/home-1


And many more...

[Brian Fretwell]

Just a thought. If that Eumig projector has an inching knob at the back and the frequency adjustable speed controller doesn't work, it should be possible to fit a gear wheel to the shaft and run it from an external motor. I've seen that done at a Widex "8mm Cinerama" set up with 3 projectors held in sync with external motor like that.

[Mattias Norberg]

Just a thought. If that Eumig projector has an inching knob at the back and the frequency adjustable speed controller doesn't work, it should be possible to fit a gear wheel to the shaft and run it from an external motor. I've seen that done at a Widex "8mm Cinerama" set up with 3 projectors held in sync with external motor like that.

i use a external motor on my Eumig Mark S 810 D Lux and i rotating the knob with a thick rubber tube that is attached to the rod and pillow bearing and cogwheel and belt
here is a photo


the rubber tube i did use did look like this and to get it straighten up i have to heat it up with a heat gun



i have only glued a Magnet inside the Eumig projector otherwise the projector is in Original shape photo here


and the sensor that the magnet trigger photo here





and how the Hall sensor is connected



i did even test to use hand crank and a paper clip on the rod that givs a little bump that clicks the left mouse button and that did work to here is a photo



here you can see the external stepper motor in action https://www.youtube.com/watch?v=xnBGaFhk70Y
before i did use a DC motor but now i use stepper motor and arduino

[Stan Jelavic]

Petty elaborate setup Mattias. Here is the AR0230 update. Got it working on RPI at 1280x720 rez. The full rez has a color issue and I contacted the arducam support for help with that.
Here is a capture of a scene with bright clouds and dark shadows.

The shadows came out good on my good quality monitor but a bit dark on my laptop. So for HDR clips I suggest to view then on a good quality bright monitor. The bright details do come out (clouds, lady's dress). With the other cameras I used the sky would just turn all white and the lady's dress would not show any details (polka dots missing).
The shading is acceptable with the 16mm lens used.

The right hand side is dark because the camera grabbed the out of focus mask edge used with the open gate. The mask is used to limit the lens flare. But reasonably even distribution of brightness throughout the active area which is what we want.
So the bottom line, this camera seems to be a pretty good HDR RPI solution combined with a 16mm good quality lens. The disadvantage is lower resolution. I would like also to add that although the camera itself does not offer external triggering, the RPI can trigger it via one of the input pins.