This is topic Analogue Optical track in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Clive Carmock (Member # 2882) on 06-27-2005, 03:53 PM:
 
Can anyone tell me of the two optical tracks on a 35mm stereo print, which is the left & which is the right channel?

I thought I knew the answer, and a fellow UK collector also agreed with me that the one closest to the picture is the left channel. However someone has now suggested that that is the right channel.

I searched Film-Tech for the definitive answer but can't find it using any of the search terms I have tried.

Any help appreciated.

Regards
Clive
 

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Posted by Mitchell Dvoskin (Member # 751) on 06-27-2005, 03:57 PM:
 
The one closest to the picture is the left. On the otherhand, you drive on the wrong side of the road over there, so it would not suprise me to find the tracks backwards...
 

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Posted by Clive Carmock (Member # 2882) on 06-27-2005, 04:07 PM:
 
I kind of asked for that one didn't I?

Thanks Mitchell - turns out that we were right all along then.

Regards
Clive
 

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Posted by Stephen Furley (Member # 1277) on 06-27-2005, 04:15 PM:
 

quote: Mitchell Dvoskin

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it would not suprise me to find the tracks backwards

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With stereo sound on 16mm mag the tracks actually do tend to be reversed; it tends to be left on centre traack and right on edge track in Europe, and vica versa in America, but this is not univrsal.
 

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Posted by Steve Guttag (Member # 268) on 06-27-2005, 04:54 PM:
 
When dealing with Kinoton projectors with stereo solar cells...one must remember that Green is Left and Red is right since they are backwards scan (not reverse scan). They put the light source on the right and the cell on the left...still a slit lens system though. Note that with the red readers...they now have the LED on the left and the cell/preamp board on the right...still backwards from the rest of the machines!

As for 16mm magnetic....how much of that do you actually see/run? The AFI just ran one for their Silverdocs festival and it was marvelous. The picture looked really good and the sound was quite smooth. It was mono so no need to scan the "balance" track.
 

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Posted by Michael Schaffer (Member # 1204) on 06-27-2005, 06:56 PM:
 
I don't quite follow you here. What do you mean by backwards instead of reverse? All the components are "backwards" or "flipped" when you look at them because the film path is "folded" over to the right, but the location of the components relative to the film is more or less the same as in other projectors. Or is that what you meant?
 

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Posted by Ken Jacquart (Member # 369) on 06-27-2005, 09:01 PM:
 
Red, Left, Port
Green, Right, Starboard

If you drive a boat, you know what i mean. It's an easy way to remember. (At least for the normal color convention)
 

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Posted by Stephen Furley (Member # 1277) on 06-28-2005, 07:04 AM:
 

quote: Steve Guttag

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As for 16mm magnetic....how much of that do you actually see/run?

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I used to run quite a lot of 16mm sepmag, but you don't see it much now, sadly; it can sound very good. Most of it was mono, but I've run stereo a few times. A year or so ago I even had to run four channel matrix stereo with 'A' type Dolby NR. I had to ask here how to set up a CP-65 and MPU-1 to run that. I've never heard SR on 16mm though.

Mono on 16mm mag is usually centre track here, I believe that edge track is more common over there, so it seems to be that the normal mono track position is used for left, and the other one for right.

I haven't run much mag stripe sound on 16mm, but even so, I've seen all sorts of odd formats; Full track is the most common, half track stripe over an optical track to give bi-lingual prints, I've seen airline prints done this way when they used 16mm, and edge stripe, the same width as balance, on 2R perf stock. Even on full width stripe you can get several track configurations. Inner and outer half-track heads were used to record separate music, dialogue and effects tracks. Somebody even made a centre third track head, so you could end up with all three components recorded as three side by side tracks on a single stripe, and play them back with a full width head. This sort of thing never seemed to work very well, and I've not seen it done since the '70s. Advanced home movie makers used to do it sometimes. I do still have full sets of heads for my B+H machines (666 and 609) though, so I can play back anything that I might come across. I shouldn't have said that, should I? Somebody will now turn up with some weird type of track that I've never seen before.

At least the full width stripe on 16mm gave a nice wide track, unlike 35mm.

There are even Super-8 prints with matrixed four channel tracks on them, Lt on the main stripe, and Rt on the balance.
 

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Posted by John Pytlak (Member # 331) on 06-28-2005, 07:11 AM:
 
Standard SMPTE 203-2003 specifies 2-channel track identification:

quote:

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Channel 2 shall be recorded in the record nearest the outer edge of the film...

Track usage
The two tracks specified in this standard may be used for either related stereophonic material or unrelated
material such as two languages. When used for two-channel stereophonic program material, track one shall
be used for the left (as viewed from the auditorium) loudspeaker channel. Track two shall be used for the right
loudspeaker channel.

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