Modifying Camera Speed Regulation.

[Konton]

I was curious if anyone had ever tried to open a Super 8mm camera up and try and modify whatever regulates the speed. Is this even possible?

Also, are there any varable speed Super 8mm cameras where the speed is controlled by a knob rather than a switch?

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Konton the Grey

[Basstruc]

I don't know but it would be very interesting ! I would love to take a Canon 310XL ,disable the automatic exposure & take it to 24FPS .
Matt

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[#Pedro]

I would only do this when I had the circuit diagrams of the camera and a layout that would allow me to identify the components. I think you are trying to do sync control, aren?t you?
Pedro

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[Konton]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by #Pedro:
I think you are trying to do sync control, aren?t you?
Pedro
<HR></BLOCKQUOTE>

Hey Pedro,

To a small degree yes. I just took apart a Russian Super 8mm camera from 1988 and while playing with the broken speed control, made me wonder if it's possible for most people to open up a camera and speed up the camera or slow it down.

With a very small mirror and a tobin speed checker I can verify that the speed of a Super 8mm camera is NOT at 24fps, but that's about it. I thought if i could do that and then made minor adjustments, you could get a camera as close to 24fps as possible without crystl synching it. Just an idea.

[cameraguy]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by Konton:
Also, are there any varable speed Super 8mm cameras where the speed is controlled by a knob rather than a switch?

<HR></BLOCKQUOTE>

Yeah, the Beaulieu 2008 & 4008 cameras. You can adjust the speed with the dial while filming.


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[becomedeath]

yes, I have a Beaulieu 4008ZM4 and it has a dial to control the frames per second. But, of course, it is quite off and so I must get the camera crystal synched. hell.

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[Jean Poirier]

I don't know if they are still in business but National Camera Inc had a technical paper titled The Movie Camera. It showed the way to adjust camera speed but I must admit that I've never tried it myself. You have to adjust the centrifugal switch and/or tachometer feedback. Not easy but not impossible I guess.

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[#Pedro]

It makes not much sense to adjust a conventional regulated camera to any determined framerate. It is definitively not possible to achieve enough accurancy for double system sound. The only 2 ways are:

1. crystal sync ALL devices that run sound and picture (camera, sound recorder, editing devices, projector). Only this way it is garanteed that the speeds will not drift, alterate and has exactly the same ABSOLUTE value. Measuring the framerate and turning a knob of a potentiometer you may be successful in adjusting 24,0 +/- 0,5 frames, but the required accurancy is 24,000000 frames (!) in order to avoid drifting. The rest is wild sync.

2. Creating a locked regulation loop.
This less expensive way does not require any camera modification and lets the camera run at it?s "natural" framerate that also may vary with temperature, film load, battery charge, camera position, humidy etc.
BUT, it must be documented HOW the camera was running during shooting.
A simple and ideal way of documenting this, is the flash socket, that provides an 1-impulse-per-frame output. You record one impulse per frame in parallel to your sound. The distance between that pulses document exactly how the camera was running and are an electronic "perforation" of the sound tape.

In post production, this pulses must be used to REGULATE the picture device or the sound tape itself in a CLOSED REGULATION LOOP.
An electronic counter must be increased by each pulse and at the same time decreased by each film frame. If the counting result stays at 0, everything is fine. If not, the speed of one of the devices must be influenced until the result becomes 0 again. This way its garanteed, that both devices run frame accurate at the same speed without any crystal. This counter-based regulation we call synchronizer.

3. Trying to adjust camera speed and f.e. projector speed with kind of frequency counters can help in wild sync, but there is no way to achieve an accurate, automatic-running lip sync this way. Only creating a regulation loop, you can start one of the devices, and the other follows exactly until the end credits wihtout drifting any singlular frame.

Pedro

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[This message has been edited by #Pedro (edited February 06, 2002).]

[Cranium]

I don't think anyone was saying you could make it crystal accurate. I think the point is to get, say, a Canon 310XL to run at ~24fps, instead of the typical 18. There's loads of cheap cameras with decent quality FAST optics, that could be useful in some situations if they ran at 24 fps. The only downside I can see if it works at all is the loss of the built-in meter. But I'd be very interested in an f1.0 camera that runs at 24fps (or thereabouts) as long as it has a flash socket.

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Mikel Z