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

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Posted by James N. Savage 3 (Member # 83) on 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.

Posted by Kevin Faulkner (Member # 6) on 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.

Posted by Jan Bister (Member # 332) on 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?

Posted by Jean-Marc Toussaint (Member # 270) on 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!]

Posted by James N. Savage 3 (Member # 83) on 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.

Posted by Jan Bister (Member # 332) on 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.

Posted by Jean-Marc Toussaint (Member # 270) on February 18, 2005, 12:10 AM:

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

Posted by John Clancy (Member # 49) on 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.

Posted by Jan Bister (Member # 332) on 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]

Posted by Michael De Angelis (Member # 91) on 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

Posted by Jan Bister (Member # 332) on 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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