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How to do a self-made telecine for 8mm with basic tools and equipment


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#1 Luigi

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Posted 11 January 2007 - 05:34 PM

Dear all,
I appreciate a lot this thoughful forum and I would like to share with you my attempts to do an acceptable and cheap transfer from 8mm and super 8 to an AVI file.
I think that the most of the readers has the basic tools I have which are: a 8/super8 mm projector (the mine is YELCO P-111Q), a miniDV videocamera (the mine is Sony DCR H14E), a PC with editor like Studio 9 plus Pinnacle or more advanced. Projectors are also available at ebay for an hundred euro (at least in Europe).
First of all, let me say that my first objective is make watchable some thousands of minutes of 8/S8 movies my father made about my childwood, possibly at an acceptable price (no compatible with standard telecine prices), but I think this is a sharable objective for many, many readers. My final objective, indeed is to overlay to these videos, my mother comments until she is still with us. So I have fully understood that the best would be to have HD, that there will be loose of quality especially with the dynamics and colours, but let me say that if we compare this issue with the fact that all these movies will remain unwatchable for ever, closed in some closet, and comments will desapear when my mother will leave us, we can forget the issue of quality, which is a second order problem, and focus on the main issue which is the "flicker". Moreover, at least in my case, movies are without-sound which makes much easier transfering them from 16/18 fps to 25 fpc.

At the present I have found at least three theoretical ways to do the transfer. This is my understanding, please be free to correct me.

1) First way: As the video camera takes 25fpc (PAL), but similiar consideration can be done for 29?NTSC, and 8/S8 have 16/18 fpc, movies result with "flicker effect" which means that the average light of the immages varies visibly and it is not acceptable. If the projector can be modified in its speed continusly, you can find a speed (2/3 of 25fpc = 16,67fpc) that makes the flicker not visible to our eyes and makes the movie acceptable. Unfortunately, while videocamera has its acquisition rate controlled by crystal (by the internal CPU), the most of projectors do not have it. Worse they have a AC brush motor (alternated current with brushes, asincronous) which are controlled in speed by varying voltage/current at their brushes by a metal thread potentiometer. The result is that as the heat of lamp and motor varies the internal temperature the speed drifts and the unstable 2/3 ratio changes making the flicker early come out. An alternative method could be to use 25 fpc speed for the projector (does it reach it?) and slow down the speed of the avi file by software tools included in Studio Pinnacle or similiar, but the drift problem will remain.

2) Second way: leave the projector to drift as it likes and try to keep the videocamera locked to its speed. My theoretical idea would be to find a videocamera (it will probably costs less than any telecine equipment or services) that is able to catch a single frame, with an external sync input. But nor my e-mails to Sony Italy commercial did not so far give answers, neither my research on the web and catalouge could result in a model able to do this.

3) Leave videocamera and projector go where they want and correct them by software. From my understanding the real frames of 16/18 fpc projectors are 2 or 3 times higher to avoid flicker effect in our eyes and so the same frame image is repeated 2 or 3 times in a row before change. This makes doable to select in 25 fpc from videocamera those frame which are the same or different and rebuild the original corrected stream. At least in theory.

Here are my theoretical solutions to the above three ways:
1) First way:
A) build a motor speed controller. Two types:

A1) take a 1-0-1 signal by an inductive sensor or similiar from the highest speed gear in the projector and use it to retrofit a simple AC speed controller (like one of those used for drills). There are kits for these AC controllersfor few ten $.
The difficult part of the control should be upward. In fact we need a frequency-voltage converter (it is a simple circuit integrated speed controller for few $) which will transform the signal from the gear (inside the projector) in a continuos DC voltage. This voltage will be higher as the speed of the projector will go up, and lower if the speed slows down. By comparing this voltage to a reference voltage (that I can vary, from a potentiometer) I drive the speed control (the one available for drill) in order to mantain the reference voltage and the output of the converter as closer as possible. This will not give to the projector the stability of crystal, but will overcome (I think) the most part of the drift.


A2) do the same with software by a 8bit processor which "counts" the frequency coming from the signal in the projector and compare it with a reference in a certain time. The output has to retrofit the speed control drive as well. This requires ability to write machine software.


B) buy a almost "turn-key" solution. There is one motor with crystal control sale on the net at (http://www.tobincine....com/page3.html). This is done for Bolex H-16 really and should be adapted for any other solutions ( I do not know with which results, but it is perhapse feasible and expensive)

2) Second way: May be by a Sony D35 camera with clear scan function it is possible to do this? (scanning from 60,4 Hz to 200,3 in 183 steps). This option would be very simple and easly extendable to telecine for other formats like pathè-baby 9,5mm ( I have many videos with this format and in Italy telecine services asks for 8,8 euro per minute!!!)
Do you know any videocamera able to do this? May be a camera could take picture of each frame, ( I see from http://www.jkcamera....tal_printer.htm the Canon EOS 30D) but how can I keep all the picture taken and put together in sequence in a AVI file by software? Could the DTA adapter help in some way? but at which price?
In the reality, all we have a analog acquisition card in our PC. Linked to a digital camera could it acquire single frame? Which software to use to sync it and to rebuild an AVI file?

3) Third way:
I found on the net a card which is able to acquire frame and stream and sync by software (http://www.foresight...cuStream170.php) . the problem is that its price is (about $ 4,000) not compatible with my project objectives.
Studio Pinnacle, for what I have seen is not able to do any frame recognition (but it has the potential, being able to find when a scen finishes and another one start). May be some other software? Any suggestions?


Thank you for the patient to read my long file, sorry for my Italianglish. I hope this can structure a bit some kind of solution.

Luigi from Italy
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#2 Bryan Darling

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Posted 11 January 2007 - 09:12 PM

I would get a workprinter, get a model you can afford. Any of them are worth the price as far as quality goes. I use one for both business and personal use. I have the workprinter XP however they have other models depending on your budget. The results using any model will be far superior to that of a standard projector and video camera setup.

http://www.moviestuff.tv
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#3 Michael Collier

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Posted 11 January 2007 - 11:11 PM

Check out this theoretical discussion on how to do the same thing:

http://www.cinematog...n...crazy&st=15

that discusion has several ideas for how to do this. For the most part I would rule out the use of a camcorder for doing the actual electronic capture. Syncing up projector and camera is a difficult proposition to do cheaply. I argue for the use of digital SLRs, which can be simply triggered by connecting a mini-jack to the shutter release jack and shorting the wires momentiarily. A box can then be built to automatically control the projectors motor to advance the projector one frame, stop it and expose the camera, then repeat. A simple design can be built for under 50 bucks. with a quality DSLR you can get HD transfers. The only downside to this system is it might be a bit slower than normal. maybe exposing only 3-4 frames per second. The whole proccess would be automatic. Frames from the DSLR can be arranged automatically by an NLE and rendered to any format desired.
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#4 Giles Perkins

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Posted 12 January 2007 - 12:57 PM

See the DIY Telecine tab of www.onsuper8.org for more alternatives and links
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