lip sync audio without clapper-board - is this possible?

Perfectly possible.

It's best to have some visual cue at the start which will tally with something recorded in the audio, such as just a snap of the fingers in front of the camera, which gives a reference for synchronising the two ..video and audio.. afterwards when you edit..

(..Here's Harrison Ford clapping his hands in "Blade Runner" as a sync signal for picture and sound..)



If you don't have this sort of sync signal, then you may just have to spend a few more seconds during editing to slide along the audio, and play it a few times, till it's in perfect sync.

With old analogue tape or cassette recorders there was always the possibility that the audio recording might gradually slip out of sync with the recorded picture, but a Zoom is digital, so should keep in perfect sync all the time. Of course, every time you stop and restart shooting you'll need to sync up the audio again.

in addendum to David's excellent advice..

.. Very discreet and informal documentary filming ..

hold the audio-recording device in front of 'video' recording device and bump fast into the lense..
(I know, most of you lough out now, yelling "krazy kraut", etc ........ ) 😉

for sure, do that with care - but speed, exercise this, move like a dart player, audio device is dart...
intention: it is a very silent sync-signal.. on 'film', if done fast enough, you have max 2-3 frames of 'bump'=black, on audio-rec you have the 'BUMP' ..

any 'clapper'/clapping is perhaps too noisy...

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@ Mr Babsky!
I do remember mile-long discussions about © in THREE sub-boards here..
(internal joke...)

Fato wrote:
.. Do I have to set the Zoom's audio recording frequency to that of the digital camera or mobile phone in order for sync not to slip over time?

if possible, that is best practice! 🙂

No - whoops, sorry Karsten! - in my experience, anyway, it doesn't really matter. The Zoom will keep to its own internal clock, and so will the camera. As they'll both be pretty much rock-steady on their own internal timing, they shouldn't slip out of sync, even though they're not sync'ed to the same clock rate or to each other. (..In the "good old days" external recorders, like a Nagra tape deck, had to be sync'ed to a crystal clock within whichever (film) camera you were using ..but that was in the days before digital recording..)

By the audio recording "frequency" you probably mean, say, 41.whatever KHz or 48KHz ..but that's just a "sampling rate" and has nothing to do with the internal timing clock of either of the devices. The internal clock in each should keep everything running smoothly.

I've no idea, of course, exactly how accurate the frame-rate timing is in, say, mobile phone camcorders ..though I've shot a movie on a Sony-Ericsson phone, imported it into iMovie and it turned out really well ..all things considered!

So, no; no sync is necessary. Just let them both run at whatever internal clock rate they both have.

I record "wild" video audio - usually as a separate audio track for weddings, etc - onto Mini-Disc, Zoom..



..and Sony NT-1 digital tape..



..Sony DAT and all sorts of devices, never sync their "frequency" to anything at all, and it all syncs together perfectly in iMovie!

I was invited to a 'Degree Show' (art students' end of year show) in which a friend was exhibiting her 8mm movie ..or rather, an "activity" which was the editing - chopping up with scissors and sticking together different bits - of an 8mm film while it was running through a projector.

This was a "hommage" to ..erm, I can't remember; some film-maker who also chopped up bits of film..

Anyway, her tutor/supervisor wasn't there ..so there was no way that he would see this event, unless it was recorded. I had my phone with me, and a large-ish memory card inside, so I shot the 15-minute or 20-minute event on the phone ..in poor-ish quality ..but that just matched the "low-grade" quality of the 8mm film she was using, and its becoming more scratched and wrecked as it passed through the projector, onto the floor, was grabbed and cut and stuck back together, then going through the projector again, etc..

I imported the material into iMovie and added titles, etc.

There's a scrap of it (..showing scratched movie back-projected onto a screen embedded into a mock wall..) at the start of this movie ..which is itself just a test of titles in iMovie '08, I think: several people had said that titles were causing problems for them, so I put titles over an assortment of different video footage: some from the phone, some from old VHS tape, some from short clips shot on a stills camera, etc ..but I had no problems. The titles are just numbered "Title 1", "Title 2", etc, to show that adding eight titles over a variety of different movie formats produced no problems - for me, anyway!

P.S: The preferred audio sampling rate within DV/HDV movies shot on tape and imported into iMovie is 48KHz, but I've no idea if iMovie prefers audio at 48KHz rather than at 44KHz or some other sampling rate ..I've imported audio recorded at all sorts of sampling rates and never had a problem. (..A fix for no sound in previous versions of iMovie was to set the Mac's audio rate to 44.1KHz - or play a few notes in GarageBand - and that would magically fix the problem, even though the preferred sampling rate for audio within DV/HDV movies is 48KHz..)

never needing it, but heard of being good.. :
http://www.qtsync.com/qtsync.php

You say "..I know how to do this in QuickTime pro.."

But in QT Pro it's absolutely simple. As you say, you can "..use this ... for stretching or shrinking the off-camera audio recording."

In QT Pro, open the video and trim it to the length you want ..in other words cut out any extra beyond the end of the interview. Then open the audio in a separate QT Pro player window. Trim it to match the ending point of the video. Then Select all the (trimmed) audio and use ⌘+ C to Copy all that audio.

Switch to the other, video, QT player window, and choose Edit and then Add to Selection & Scale (..or press Alt Shift+⌘ V..)

That will add the audio to the video, and will scale the audio to match exactly the duration of the video. If the audio was off by half a second, it'll now exactly match the length of the video, so it'll be in sync at the start, in sync at the end, and halfway through it may be off by about a quarter of a second. The pitch will - probably unnoticeably - shift very slightly up or down if the audio is thus speeded up or slowed down slightly to match the duration of the video.

"..I’m trying to shoot very simple interviews while on photo assignments, either with an LX3 or a mobile phone and I’m looking fora way to improve the sound quality.."

It sounds like you're really just creating problems for yourself. The LX3 is a nice little camera ..but you're carrying two devices: a Panasonic LX3 camera and a Zoom H2 which is nearly twice the size of the LX3.

What you should do is choose a small camcorder - something like a little JVC miniDV-tape camcorder, or a Sony TRV-14 or similar (..tape-based cameras are very cheap now, or get a small Panasonic AVCHD camcorder..) - and plug a small directional 'zoom' mic on top of it. The size of camera and mic will be smaller than your combined LX3 + Zoom H2 recorder, and you won't need extra hands to handle two devices.

Choose a camcorder which also takes still shots ..instead of using a stills camera which also shoots moving pictures.

With that all-in-one setup of a camcorder with a zoom mic on top you just press the button to start shooting, and press again to stop. Everything will be in sync - always.

With your LX3 - or mobile phone - plus Zoom H2 scenario, you've got to switch on the camera/phone, then switch on the H2 ..and in the rush to do it right you'll make a mistake, or won't set the H2's recording volume high enough, or will choose the wrong audio setting (Mono/90-degree stereo/120-degree stereo/front only/front & back), you'll have two batteries to worry about, you may not be sure that the H2 is recording ..and then you've got to stitch together the separate recordings afterwards.

You want something foolproof, with one Start/Stop switch, nothing to worry about, but which gives good sound in-sync with the picture.

Get a little camcorder.