8mm Forum: Pedro's Sync Unit- In simple terms

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Topic: Pedro's Sync Unit- In simple terms

James N. Savage 3
Phenomenal Film Handler

Posts: 1375
From: Washington, DC
Registered: Jul 2003

posted February 16, 2005 02:24 PM

Hi Guys,

I'm ashamed to say this, but, I can't quite figure out what this "sync unit" is. I keep hearing about it. It might be something I need. Can someone please explain what it is used for, and is other equipment needed to use with it. I'm not all that technical minded, so be easy on me [Wink]

.

I was just waiting for a "Pedro's Sync Unit For Dummys" book to come out, but it just doesn't seem to be happening [Cool]

.

Thanks.

Nick.

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted February 16, 2005 05:16 PM

Hi James,

Pedros sync unit is designed to crystal lock the GS1200 to one of four running speeds. This it does very acurately. The speed are 16, 18, 24 & 25 FPS.
This unit tends to be used mainly to run the GS at the frame rate of the TV system of 24 or 25 fps.
If we want to record a stereo soundtrack on say a feature with the new sound originating on a PAL DVD we can get the GS to run at 25 fps which is the TV frame rate in the UK and this will enable the GS to run in sync with the DVD. I have recorded a few full features in this manner.
We us the 24FPS for running NTSC discs in sync. 16 & 18 are of course the 8mm silent speeds. The various speed are also there to enable people to do video transfers aging using the GS. This is all possible because of the Elmo Sync System (ESS) built into the GS. The box Pedro designed simply plugs into the ESS Socket and the machine switched to ESS control at which point the speed control is now taken over by the crystal control of the external box. Quite clever but at the same time quite simple.

Kev.

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GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005

posted February 16, 2005 08:44 PM

Assuming that Pedro's sync unit didn't even come to be until many, many moons after the GS1200 first hit the market, I wonder what Elmo originally designed the ESS system for? Were they planning to (or did they) offer accessories doing roughly the same thing as Pedro's unit?

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Call me Phoenix. *dusts off the ashes*

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Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

posted February 17, 2005 01:51 PM

quote:
We us the 24FPS for running NTSC discs in sync

OK, this is where I'm lost. I understand the PAL/25fps speed setting, but, isn't NTSC 30fps?
[Eek!]

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The Grindcave Cinema Website

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James N. Savage 3
Phenomenal Film Handler

Posts: 1375
From: Washington, DC
Registered: Jul 2003

posted February 17, 2005 03:24 PM

Thanks Kevin & all-

That pretty much answers my question. I guess I don't need one, since I don't own an Elmo at this time.

Thanks.

Nick.

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005

posted February 17, 2005 09:38 PM

Jean-Marc: you're correct in that NTSC is 30fps, but it is for that very reason that film material is put through a process called 'telecine' in order to broadcast it as 30fps video (basically, a process of doubling and blending adjacent frames). Anyway, what it means is that film still runs at its original speed of 24fps, only that on TV you're seeing these 24 frames spread over 30. [Smile]

With PAL, no such process exists, the film is simply sped up from 24fps to 25fps to accommodate the PAL TV framerate.

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Call me Phoenix. *dusts off the ashes*

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Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

posted February 18, 2005 12:10 AM

Ahhhh... OK. I get it. Thanks Jan. [Smile]

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The Grindcave Cinema Website

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

posted February 18, 2005 02:26 AM

I've been testing the sync' unit for use with 24fps material but haven't had any success so far. Should be going through the process again later today with Keith Wilton as we're obviously interested in the possibility of using this functionality for the 50th BFCC celebration.

It works fine with 25fps - a much simpler process.

The ESS port on the GS-1200 was always intended for pulse sync' in this manner which is why it was incorporated. The GS was primarily aimed at advanced amateur film makers so they could lay down soundtracks using pulse facilities.

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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005

posted February 18, 2005 08:58 PM

That was quite the visionary thing to do of Elmo, considering they couldn't possibly have known that 20-30 years later, any such thing as DVD players and 5.1 digital soundtracks would exist enabling you lucky GS1200 owners to do just that: record new soundtracks in perfect sync with the film. [Smile]

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Call me Phoenix. *dusts off the ashes*

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Michael De Angelis
Phenomenal Film Handler

Posts: 1261
From: USA
Registered: Jul 2003

posted February 19, 2005 12:06 AM

It is a desire of mine to re-record sound tracks in perfect sync, unfortunately
I have not been able to sync from VHS or DVD in lock sync.
I am very interested in knowing how a 24fps, can lock sync with 29 or 30 fps NTSC broadcast standards without spending an inordinate amount of time on a project? Let alone keeping the pitch of the recording steady and even.

Is it possible to record the NTSC sound track into a movie editing program such as Adobe Premiere, and then save and export the captured track from the computer at the desired NTSC frame rate to then sync along with the film?

Best,
Michael

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Isn't it great that we can all communicate about this great
hobby that we love!

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005

posted February 19, 2005 12:45 PM

Michael, sounds like a good idea. You could simply change the frame rate associated with the sound recording once it's in your computer from 29.97fps (NTSC TV) to 24fps (you guessed it... film). Then let the computer sync your Elmo to it, and do the recording thing.

And, oh yeah... it is the sound source that keeps your projector in sync, not the other way around, so keeping the pitch isn't an issue.

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Call me Phoenix. *dusts off the ashes*

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