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Filming TV Screen with Bolex


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#1 DavidM

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Posted 23 July 2010 - 10:13 PM

I am working on a project which calls for us to film a TV screen. The camera is a hand cranked Bolex. I was wondering if there is anything we need to do to ensure that we don't get any flickering on the TV screen. The TV will either be a LCD or a Plasma with a response time of 60Hz.

Thanks!
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#2 Brian Drysdale

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Posted 24 July 2010 - 02:19 AM

LCD screens tend not to roll like cathode ray tubes, however, I wouldn't like to say what the result with a clockwork camera would be. Any time I've filmed them has been has been with a crystal controlled motor.
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#3 Olex Kalynychenko

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Posted 24 July 2010 - 04:30 AM

I am working on a project which calls for us to film a TV screen. The camera is a hand cranked Bolex. I was wondering if there is anything we need to do to ensure that we don't get any flickering on the TV screen. The TV will either be a LCD or a Plasma with a response time of 60Hz.

Thanks!

I agree Brian information.
The filming a TV screen with Bolex with mechanical spring motor or hand cranking do not possible. You can't synchronize a speed of shooting of camera with frame scan.

You need cine camera with crystal sync speed control.
But, The many cine cameras with crystal sync speed control can shoot to catch a frame line at TV screen shooting.
Need crystal sync speed control with special Phase adjust fuction.
Our microprocessor controllers have Phase adjust fucntion.
We attach of this fuction to main programm for shoot of a TV screens and synchronize with video assistance devices of camera.

Now, tsi work fine. You run a camera, can check position a frame line on viewfinder or to see winking on TV screen of a video assistance.
You press on " Phase " button of motor control and controller to slow down a speed of camera on a very small value and you see the frame line go to out screen position. Only you do not see frame line, you release "Phase" button, the controiller set crystal sync speed value and you have excellent footage without frame line.

A some time ago, at our previous projects, we use other idea of a synchronize speed of camera with TV screen. We take special pulses from main power or TV signal and send to motor controller.
The electronic adjust of speed of motor with frequency of outside sync signal.
This work, but, ask of long signal cords.

Now, we use of Phase adjusting of a speed fuction at our controllers.
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#4 Art Leal

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Posted 28 July 2010 - 05:43 AM

I am working on a project which calls for us to film a TV screen. The camera is a hand cranked Bolex. I was wondering if there is anything we need to do to ensure that we don't get any flickering on the TV screen. The TV will either be a LCD or a Plasma with a response time of 60Hz.

Thanks!


Hi David:

I used a Bell & Howell Filmo and got the following from shooting a computer LCD screen with a 60Hz refresh rate. The sample runs from 00:58 to 01:04.


There's an even shorter sample using a Super 8 camera with very expired film and an LED TV (0:55 to 0:59).


Both were set to 24 fps. Does it work? Not sure (given the samples are so short in time and I used aged films), but I thought I'd pass them along.
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#5 Glenn Brady

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Posted 06 August 2010 - 09:20 AM

There are instructions for using a Bolex camera for such purposes at Clive Tobin's Tobin Cinema Systems website (Tobin Milliframe Controller TMC-2 Instructions). You'd need a Milliframe Controller connected by cable to a compatible Tobin crystal motor on the camera to achieve the intended result.
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