Pilot Tone from Nizo Pro/801M/561M

[xoct]

The Nizo Professional, 801 Macro and 561 Macro were the only Nizo cameras that omitted a pilot tone signal. What audio recorders were made that recieved this signal?

[Robert Hughes]

O-mitted or E-mitted? Please specify...

 

The Nagra accepts pilot tones. Any 2-track audio recorder can accept a pilot tone on one channel, and you can resolve either in hardware or software during post production.

[xoct]

Oops, emitted is what I meant to type. Could you explain what it means to resolve audio? I'm kind of new at the sound side of things. Are there other recorders other than Nagras that will recieve pilotone?

[Robert Hughes]

First, a little background. Audio recording on a film shoot can be either single-system or double-system.

 

Single system means that audio is recorded on the same film reel as the image; either as an optical track (i.e. old 35mm newsreel cameras) or magnetic (Super 8 or 16mm "mag stripe" film, no longer made). Video camcorders are equivalent to single system film.

 

Double system, what you are planning to do, requires a separate audio recorder that runs either locked to the film speed (synchronized) or completely independently (wild sound). Prior to the era of crystal synchronized cameras and audio recorders, the camera and audio recorder would ensure audio sync by an audio tone communicated by wire from the camera to the audio deck, either 1 pulse per frame or a 60 Hz pilot tone generated at the camera. The audio deck would record this sync tone, either on a special purpose center track on a Nagra, or as an audio tone on any available 2-track audio deck.

 

Later, in post production, the audio tape is played back on a special variable speed tape recorder equipped with a resolver, a frequency sensing circuit that speeds up or slows down the playback tape to compensate for speed variations that occurred during recording. The result is an audio track that is frame-synchronized to the film. Traditional resolvers are hardware based electromechanical devices that result in a sprocketed full coat magnetic track; computer-based software can provide an equivalent synchronized track.

 

Note: resolving creates an audio track that has a frame-for-frame correspondence to the film reel. By itself, it does not synchronize audio; that is the function of the the film editor, using the image and audio generated by the clapper slate. The clapper sounds the start (or end) of a scene and give the film editor a definate starting point to place the film and mag track for that scene. At this point the scene is synchronized.

Edited March 21, 2005 by Robert Hughes

[Lars Fuchs]

Hi, I am very interesting in software-based resolving of pilot tone, which you describe. Could you mention any specific applications that can perform this function?

Traditional resolvers are hardware based electromechanical devices that result in a sprocketed full coat magnetic track; computer-based software can provide an equivalent synchronized track

[Phil Rhodes]

I suppose it could be done, but I've never heard of an application that would do it. I wrote a piece of software that's capable of decoding SMPTE timecode in software, which is a more complex system that would prove the concept.