consider this

If you want to copy my Telecine Machine, I have to warn you that a certain amount of skills are needed to end the project successfully.

Alternative for the webcam

Instead of using a webcam, you can also consider using your camcorder. If it can zoom about 16x, it is possible to replace the lens/camera assembly by your camcorder. Connect the camera with your computer using the USB or Firewire connector. Switch off autofocus and image stabilisation.

Building descriptions

To be able to use the Eumig Mark 8 as a telecine machine there have to be made quite a number of changes:
  • The drive system has to be changed so the projector can run at low speed. The optimum result with my machine is somewhere between 4 and 8 frames per second. I decided to use a DC motor, so by using a pulse width regulator the speed can be regulated nicely.
  • To see what speed the projector is actually running, I implemented a "frames per second" counter.
  • Something has to be done about the heath the projector lamp generates. The original lamp is 100 watt and has a burning effect on the film at low speeds. The solution is to replace the lamp with a LED. I choose the Luxeon 3 Watt LED. This LED is current driven and can be regulated by changing the current.
  • The hotspot has to be illuminated. For those who do not know what the hotspot is, it is the reflexion of the lamp on the screen. If you stand next to a projector and look at the screen, the hotspot is a light area somewhere in the middle.
  • To be able to tell the computer that a frame is ready for capturing, the projector must provide a synchronization pulse that can be lead to the computer.
  • To make the available time for the computer to capture a frame as long as possible, the shutter in the projector has to be removed.
  • The lens has to be modified. Together with the new webcam a whole lens system has to be constructed.
  • A power supply is needed to foresee all the electronics of the right voltage.
  • Beside this all, a few more things have to be taken care of, to make recording on a computer possible. I use the program Cinecap (MAC users may use Capturemate) to capture the frames. . There are various other programs available.
  • A computer mouse has to be modified to serve as an interface for the sync-pulses. I used a USB mouse. This mouse can just be plugged in at any time and works in parallel with the original mouse.

  • Next, a few tools proved to be very handy during the construction of my Telecine Machine:
  • A miniature drill. Especially the grinding tool proved to be very useful. The cleaning out of the old projector was almost completely done with this tool.
  • Pillar drill machine or a good hand drill and a drill stand.
  • Various taps
  • Solder iron
  • Jig saw (and enough replacement blades....)
  • Super glue

Cleaning out the projector

To make space inside the old projector a lot of parts can be taken out. I removed the complete drive assembly and powersupply. I also removed the powerconnector, to replace it later with a more common type.


The removed parts



Cleaned out projector (backside).
The new drive assembly is put in place already.



Cleaned out projector (frontside)
On the front side I removed all the parts behind the front cover. Finally I removed a lot of aluminium parts using a miniature grinder tool. Be carefull to leave enough screw holes left to be able to mount a new front cover.

The shutter

Because the webcam makes a "photograph" of each frame, the shutter in the projector is no longer needed. In fact, because it unnecessarily interrupts the image, we don't even want it anymore. If we take the shutter out, we can use all the time between the moments the movie is transported to the next frame to capture it. This way we avoid recording blocked and thus black frames. This is very important to avoid flickering. In the case of the Mark 8 I took the shutter out and cut off the blades of the shutter. The Mark 8 has 3 blades, but some other projectors have 5 blades. I had to put the center part of the shutter back in place, as it also has the function to advance the film to the next frame.
vlinder_compleet

The complete old shutter. As you can see, it has another function too: guiding the transport system.
Therefore it is not possible to just remove the shutter, but it has to be modified.
(photo D.Pronk)
vlinder_compleet

The modified shutter: the shutter blades removed.
(photo D.Pronk)

The drive assembly

During the telecine process the projector must be able to run slowly. Therefore the drive unit has to be changed. The original AC drive is not so easy to regulate. In a shop for model cars I found a motor: Buehler type 1.13.055.220. It has enough power and the right amount of RPM's to serve my goal. It runs at 3100 RPM at 12 Volt and provides a torque of maximum of 40Nmm. If you use a replacement for this, be sure that the torque is high enough to run the projector (I gambled it and it turned out OK :-)). If the speed is different, you might need to recalculate the gearing. Besides Bühler, there is another manufacturer that sells nice DC motors: Igarashi. I would have a go with type SR555SHP-3247S-75. As it runs 5700 rpm, you obviously should change the gearing. In the same shop I bought some gear wheels and shafts. Together with a few pieces of printed circuit board, the jigsaw and a soldering iron I created a bracket and gearbox for the drive unit. Surprisingly the bearings were made of material that could be soldered with a genuine solder iron. The only thing you have to take care of is to lubricate the bearings again, as the grease may have come out during the soldering. The reduction of the gearbox is 1 : 2.5. The extra gear wheel is just there to create some extra space between the motor and the central driveshaft of the projector. Because the motor has to deliver a relatively small amount of power, the RPM at 12 Volt is higher than expected. In the end that is an advantage because in comes in handy if you just want to find a specific scene. Another result of the low load is that the motor only draws about 1A. That also has a positive effect on the electronics used.

The complete drive assembly
The motor is driven by a Pulse With Modulator (short: PWM). This type of regulating is simple and dissipates almost no heath. Besides the variable resistor (R2) that is used to regulate the speed, there is a 3 way switch (SW1). This switch is used to choose between forward-stop-backward.


A bigger image can be downloaded from the download page

The circuit around the timer IC NE555 is very straight forward. There are no parts that need cooling. Only when the circuit has to deliver more than 2A, the MOS-FET T1 and diode D3 need cooling. Instead of the BUZ11 you can also use an equivalent like the IRFZ34N.


Sync pulse generator

To be able to tell the computer that there is a frame waiting to be copied, there is an encoder mounted on the central driveshaft. Every revolution, at the moment there is a frame in front of the gate, the gap in de encoder triggers a photo detector. Of course a micro switch or reed contacts could also be used, but they often suffer of contact bouncing. Solving that problem will result in a circuit described here.


The photo does not show the 4093 that is in de circuit diagram below.
The pulses that are generated this way are transformed by a little circuit in nice 20 millisecond long pulses. In the end the pulses are presented at a connector on the front of the projector. This is done by a transistor in an open-collector configuration that can be used to feed into the computer mouse. Be sure that the mouse you use is one that switches to ground when you press one of the buttons. This circuit can than be used to synchronize the computer. There is also a little switch (SW1) foreseen that inhibits the pulses, so you can run the projector without triggering the computer. The gap detector is a TCST1000. You can use an alternative component like the CNY36. Also the TCST2000 or CNY37 are suitable. They are just a bit bigger because of the mounting holes.


A bigger image can be downloaded from the download page

The frame speed counter

Because the speed of the projector can be regulated over such a wide range, a frame speed counter comes in handy. Starting point are the pulses coming from the sync pulse generator. They are counted by IC2. At the same time IC1 gives a pulse every 1 second. This time is set by the combination R1-R2-C1. Fine-tuning can be done by soldering a resistor of high value in parallel with R2. C2, R3, D1 and IC4a form a differentiator that make a nice short pulse out of the rising edge of the seconds-pulse. This pulse is used to transfer the value of IC2 to IC3. Next C4, R4, D2 and IC4b form a short pulse triggered by the falling edge of the pulse above. This pulse is used to reset the counter in IC2. Via T1 the decimal point on the right-hand display blinks in the rhythm of the sync pulse, 1 time for each frame. The 7 segment displays are HDSP-5501. They are bright and only use a low current. If you want to replace them by another type be sure the current is need does not exceed the maximum current of IC3 (4543). You will also have to recalculate the values of resistors R9 to R15.


A bigger image can be downloaded from the download page
I placed the circuit directly behind the front panel. That makes it possible to solder the displays straight onto the PCB. I made a square hole in the front panel, so they have a nice look into the outside world.... A piece of red foil from the display of an old alarm clock makes the lot look a bit more professional.


The circuit built into the space behind the front panel of the projector.
The rest of the space is used for switches and knobs. The inside has been grinded empty using a miniature drill.

The projection LED

The original 100 Watt halogen lamp produces a lot of light and a lot of heath. Running the movie at very low speed might damage the movie. So I went searching for an alternative light source. Pretty soon I found myself digging around the website of Lumileds (now Philips). Since a few years they manufacture LED's that produce a proper dose of light. In addition of this, the white light generating LED has a color temperature of 5500K. Very suitable. At the moment there are enough suppliers around. I used a 3 Watt LED (the Luxeon LXHL-PW09). This LED can be powered by maximum 1000 mA. To be on the safe side, because of possible cooling problems, 700 mA is recommended. At this current the LED emits so much light (60 lumen) is has to be dimmed not to over steer the CCD. The power supply of the LED is very simple:


A bigger image can be downloaded from the download page.
It's a simple current source using a LM317. I deliberately did not use PWM, because it's unnecessary complex for this purpose. The circuit only dissipaters a few watts. The advantages of PWM are too small compared to the simple solution of using a LM317 in this case. R2 can be used to regulate the current and so regulate the amount of light emitted by the LED. IC1 has to be cooled. I just scraped a bit of paint from the inside of the projector and screwed it into place there. Don't forget to use insulation material, as the housing of the IC is not ground potential. Also the use of a little bit of thermal compound is needed.


The LED is mounted on a piece of PCB.
Don't forget to use some heatsink compound for better thermal contact.
The LED itself is soldered on a piece of PCB. It fits straight into the old lamp fitting. The LED is placed in just about the same location as the wire in the lamp. Now the original adjustment system of the projector can be used to shift the LED exactly in the right place. The LED also has some thermal compound on the back to make it easier for the heath to flow to the PCB. Be careful to mount the anode and cathode the right way around. The cathode is the connection that is connected to ground, the anode is the connection that is connected to the plus, in this case the current source. On the datasheet of the LED you can see there is a minor difference between anode and cathode.
luxeon

The Luxeon LXHL-PW09
To prevent the "hotspot" you can best use a piece of opal glass. I had a booklet with samples of filters for theatre lightning in my possession, so I took a suitable filter from there. During test I found out that even a piece of ordinary printing paper worked well. I placed the filter between the 2 lenses that form the condenser.

The power supply

Another part that is needed is the power supply. It must be able to give 12V DC and a maximum current of a bit over 2 Amp. As transformer I choose a ring core type, mainly because I had one lying around. It also has a few advantages. Most important one is that the mains side is nicely isolated, no exposed contacts, and you need only one screw to mount it...

In the back of the projector I made a hole to fit a power connector. The projector's original was somewhat exotic. A fuse holder and a switch on the front panel complete the mains part. Do not forget the earth wire.


A bigger image can be downloaded from the download page
The circuit is very simple, straight from the book. The only change I've made is to increase the value of R1. Because it is a little higher than commonly used, there is almost no current flowing through IC1. All current flows through T1. Advantage is that IC1 does not need to be cooled. The 2N2955 has a TO3 case. If you mount that on a bare piece of metal of the projector housing, it cools very well. Do not forget to use isolation material, as the case of the transistor does not have ground potential!

The lens assembly

The standard lens of a film projector is mounted in such a location that a big picture can be realized. Of course this does not work for projection on a CCD chip. Almost all webcams work with a 1/4" chip. The size of this chip is 2.44 x 3.2 mm.


Dimensions of a few standard size CCD chips
The visible area of a S8 and N8 film are about the same size. S8 has an effective area of 5.46 x 4.01 mm and N8 uses 4.5 x 3.3 mm. As you can see, the original (film) is in fact bigger than the projection area (CCD)! In reality the size of the frame is even about 20% bigger. The extra information is cut off by the size of the gate. So the first thing to do is to enlarge the gate. Use a thin file. Check for sharp edges when you are ready, as they may damage your film. It is absolutely necessary to enlarge the gate and reveal the extra image, because your TV set cuts off a part of the image as well. This is called "over scan". You would loose too much of the image if you do not enlarge the gate and are not able to capture the extra information in the first place. When I was looking for a solution to make a good and solid lens system, there were a lot of considerations that ran through each other continuously: The opening in the projector is just over 32 mm. There is plastic drainpipe available from the hardware store that is just over 32 mm wide (outside). Is there a lens available with the right focal length that fits in there? Does this lens also have a diaphragm? I don't have easy access to a lathe. Plastic drainpipes have a lot of auxiliary parts etc., etc........ First thing to do is to find out what focal length the lens needed, to make the whole thing not too long and thus unnecessary instable and vulnerable. For those who don't know the math's anymore, I found a nice little program on the internet called MiDAS Lens Calculator. Look at the download page where to download it. With this program you can input some of the parameters and calculate various data. The program uses .CAM files to define the camera you use. You can use one of the supplied standard files, or edit your own. In the end, in a shop selling second hand photographic equipment, I found a 50mm enlarger lens. It fitted perfectly in my tube. Using the lens calculator I found out that the distance between the gate and the lens needed to be somewhere about 135 mm (S8) or 120 mm (N8). Distance between CCD and lens was something like 80 mm (S8) and 85 mm (N8). To check one and other I made a simple test setup.


On the left side the projector, in the middle the lens and on the right side, tied to the kart board tube, the inside of the webcam.
Putting things together was a whole adventure. Various PVC drainpipe parts have been lying around on my workbench and in the end it resulted in what you see below.

None of the parts have a critical length. A few millimeters more or less do not matter. There is only one critical thing and that is the side of the pipe where the camera house it glued onto. That has to be a 90 degrees angle and perfectly straight. For all the other joints I used the principle: If you don't have a lathe available, use the length of the pipe to connect things straight. The various parts fit very tight and leave no room for bending. The lens is fitted in a 32 mm pipe. An adapter (32-40 mm) is glued on one end of the pipe. It makes that side square and therefore is used as a support for the lens. It is also used to fit into a 40 mm socket (no need to glue). The socket is made longer on the side of the camera. It gives more support if the camera is shifted in and out when focusing. The easiest way to do it is to cut a second socket in half and glue it to one side of the other socket. To get a straight result, use a 40mm pipe and push that into the sockets. Now you can first make the 2 parts fit perfectly to each other, using sandpaper to grind off one side. If they fit, take the pipe out and take some thin plastic of an old plastic bag to wind around it. Then shift the sockets back on, apply some glue and press them together. The thin plastic now prevents the sockets to be glued to the pipe. The last thing to do is to make one square end on the 40 mm pipe that will be glued onto the camera house. I see a few practical possibilities: Pipes coming straight from the hardware shop very often have two square sides from itself. Use a pipe cutter only to make a square marker on the side of the pipe. Then cut it further using a saw. Using the pipe cutter to cut through the whole pipe leaves you with a lot of deformed material. Become friends with someone owning a lathe. The method used at the lens side is also possible, but there is not much space. Do not glue the camera house on yet, as you don't know exactly where the image will be projected. Focusing is done by shifting the camera forward and backward a bit. It is not a very elegant method, but once ajusted it is OK. Maybe in the future I'll come up with a nicer solution. So you see, even without the use of expensive equipment you can make a perfectly straight and solid lens assembly.

Camera conversion.

In the end the image must be projected onto a CCD (or CMOS) chip. I choose for a disassembled webcam, as the are nicely foreseen with a USB connector and are not too expensive. I also have had the idea of using an old video camera and connect it through my capture card, but decided to try the less complicated solution first. The highest resolution webcams have is currently 640 x 480 pixels. In PAL-country that is less than the 720 x 576 pixels a PAL picture has. For now I am satisfied and waiting for better webcams to come. The webcam I use is a Creative Webcam Life! Pro. Another possibility is to use the Philips ToUCam, but I could not obtain one at the time. If you are choosing for a webcam, be sure it is fast enough. Choose a 30 fps type, as they process faster. That means they need less time to process a frame and can start on the new frame immediately. Faster camera's are most often also more light sensitive. That means they have very short exposure times. That is very useful if you want to speed up the telecine process later on. Don't make the mistake of mixing up the photo resolution and the video resolution. Video resolution of a webcam is the same as the hardware resolution of the CCD (or CMOS) chip. The extra pixels in photo resolution are created by the software! After taking the camera out of it's housing, leave the lens on as much as possible. It serves as a dust cover. Although a bit of dust can often still be blown off the chip, a fingerprint is difficult to remove. Because it's almost impossible to place the chip exactly in the right place, I made an adjustment system. That's a nice job for a rainy Sunday...

On a piece of PCB a glued 2 plastic I-beams I bought in a shop for model cars. Between these two beams a piece of PCB can slide forward and backward, adjusted by a screw, a spring from a ballpoint, a nut and a nut that has been drilled out. On top of that, in an angle of 90 degrees, a similar setup. The result you can see on the photo above. The CCD can now be adjusted in 2 directions over more than 12 mm.

The mouse

Because I use CineCap, the sync pulses have to be sent to the computer using a mouse. Of course you can use the mouse you normally use, make a little connector in it and wire it up to the projector, I liked the idea of using a separate one. Using a USB type, the mouse can stay connected to the computer and function next to the mouse you normally use. You can built the whole thing into the projector, but I liked the idea of having it outside, as I want to be able to experiment with the interface later on. .


I built the mouse in an seperate box, mainly because of future experiments.
The used mouse is an old optical one. I replaced the LED that normally shines down on the desk, by one that is mounted in one of the sides of the little box. Now I can see if the mouse is properly connected to the PC. This can only be done by a slightly older type of mouse. More modern ones use a laser in stead of an LED. Alterations to the mouse are quite simple. Just connect the open collector output of the syncpulse generator parallel to the left mouse button. Be sure that you have a mouse that has the left mouse button switching to ground (generally they all do).
Carefully remove the mechanical parts that are no longer used. Solder a thin wire on to the left mouse switch. Then connect the ground wire. Take care that you do not mix up the ground wire and the hot wire.