More on Film Leaders from an Expert

On film leaders... now I'm a bit rusty on this stuff since my own projection days, technically the "Academy Leader" is the first one you have there, with the circles, and the second one with the sweeping line is a "SMPTE Leader," but this gets used pretty interchangeably in the jargon.

One big difference is that the sweeping line can show exactly which frame you're on. This is important for editing. Also the 2 on the SMPTE leader is only one frame, for sync with sound tracks on separate rolls of magnetic film. The mag roll gets a "sync pop," which is one frame of a beep at full level.

You line them up. This is one way (and by far the cheapest) to synchronize edited picture and sound when they're on separate rolls.

(SMPTE = Society of Motion Picture/ Television Engineers. I was a student member for a long time.)

Question: Speaking of which...sound film runs at 24 fps. Correct?

Yup. Except for some versions of Cinerama which ran at 26, and Showscan which is something scary like 60.

Question:I thought the numbers counted down one second apart. However, when I examined the leader on the one reel of 16mm film that I have... the numbers are 16 frames apart.

You're absolutely right! I was rusty on this... yes, the SMPTE timing leader counts feet, not seconds, and normal "5-perf" 35mm frames have 16 to a foot. 16mm is of course more like 40 frames/foot, but the leader to my knowledge still makes one full sweep of the "hand" every 16 frames.

Now I also remember that when I cut negative there was a different sync called "print sync" and you had to offset the sync pop on the 2 from "edit sync" aka "dead sync" like you'd use in screening. The sound start marks on the Academy leader I would suspect reflect this offset which is different for magnetic and optical sound. This as I recall became decidedly non-trivial in TV news when they shot it on single-system cameras that recorded the sound something like 47 frames offset from the picture because that's where the head was. You might remember that the sound always started about a second late after they cut into a shot. Sometimes they'd put in a quick cut to B roll of nothing in particular so they could come back in on the talking head or whatever, and be in sync.

Confused yet? :-)

I kind of remember that you would cue the theater projectors on the "8" of the Academy print leader, start the motor on the first cue, and then when you hit the electric dowsers on the second cue you were right on. You had about half a second of slop before the audience would see black frames. Good changeovers look a million times better than crappy platter projection, but the economics of the business dictate otherwise.

Leaders and trailers aka tail leaders are being rethought at present. I know the EBU has a spec for a "Universal leader" and I think SMPTE might have one too.

Thanks, Hugh.