Sync - PT to picture...what are the facts

[Jay]

I have a PT24 system and would like to clarify the problems of synchronizing it to picture.I will either be using a video card (miro DC30),Beta SP or Digital Beta.I will need to be able to conform sound from T/C dat and edit dialogue,and write music for picture.Do I require a USD and a Black & Burst generator and /or master clock, even though I'm not editing pictures.I'm finding it difficult to get accurate information and need to know What I need and Why?
Are there any good referance books or sites out there.
On the subject of video cards, is the DC30 the best one to go for and what are the alternatives if I increase my budget.I want to capture video at a high quality (another information minefield!!)with total integration if at all possible.
Any advice will be very much appreciated

[georgia]

hi, we use a dc30+ , works fine. Most of our work comes from Film or Video. We occasionally lock to beta, D3, D2, even 3/4 but the majority of our work is non-linear video using protools and quicktime.

Basically a master clock will keep all your various hardware systems ( espically D to D transfers) in sync digitally. You will still need a timesource and ability to send/recieve SMPTE / Midi Timecode.
There are a number of devices out there to do this.

You can get away without a master clock for analog to analog transfers, but I wouldn't advise it. If budget is a problem get a Mark of the Unicorn DTP. It has a clock (Word 256 and Word 1), locks Protools, Video VITC, LTC, miditime code, SMPTE with little or no problems. I have used it as a central clock to keep digital transfers working from/to ADAT, VIDEO machines, PROTOOLS, TC Dats, with no problems. After listening to a bunch of other professionals and reading this forum I have researched and tested the Ardvark Master sycII and highly recommend it. It's a bit more money but a great stable clock.

As to video, we digitize to low res for almost all our work. It lowers the size of files ( 2 gig max on MAC ) and therefore makes for less data transfer. THe higher the res the more stuff to move. Unless your client really want sit in your studio and watch you mix to a brilliant video image, keep it low res during editing and mixing, when all is completed, lock back to a video deck for Final playback at high res.

we sometimes split the difference and keep a video deck ready and when we finish a reel or a section of a mix we simply push a button and watch the video at full high res locked to our mix, then go back to low-res non-linear to edit or tweak the next set of items.

Also if your trying to keep a small place running you don't need to tie up a $20,000 to $50,000 piece of gear for a day, you kust digitize at low res, and the next time you need the deck is to perform an insert edit and layback the new audio to tape.

hope this helps
geo

[Arno Peeters]

Well Georgia: most of what you wrote was not new to me: I've worked on commercials, TV series much in the same way as you have described: lowres QT with a Miroboard works fine: the quality is nearly as good as VHS, and that's what I got most of the time.

The part that's new to me is the Masterclock: do you mean that if you have more machines that need digital sync, word clock or smpte, you use one central clock to lock all the machines to ? Would I need that if I would have to put audio on movies longer than say, 30 mins ? How could I benefit from that ?
I have worked with multiple clocks I guess, but I allways lock them sequentially: PT is master, digital mixer= slave, DAT slaves to the mixer, etc...

I've been in the same 'minefields' Jay is talking about....

[Peter Steinbach]

Hello Arno-
When syncing to video, a cheap blackburst (I use a Horita..about $330) keeps all my stuff in sync niceley. I have PT5, 888, MTPAV, Emu E6400, and DA88, all reading timecode from a 3/4" video, but referencing the video signal from the Horita. Using a blackburst ensures all these different digital clocks are in sync. This kind of sync can be achieved through an AES digital signal, but that would exclude the video, unless you had a D2 or something.
So getting a blackburst would ensure tight sync. You can be sure to stay in sync for days on end. Dont forget the cost of BNC video cables..ouch!
I also use a fuse card now, and will never go back to tape if I can help it. By all means, digitize at as low a rate as possible, but remember: In dialogue editing, you really need to see lips move. I find digitizing at 1.5 meg/sec to be nice for dialogue.
good luck, ps

[This message has been edited by Peter Steinbach (edited February 18, 2000).]

[georgia]

good point Peter... We did a feature for the BBC once... The piece was digitized a bit TOO low res.. we missed a small fan that was in the corner of a scene... Looked to us (and the director) that it was off. So we didn't put any motor or fan noise in. When we sat in the theater for the final check, we all groaned when we say the fan happily purring away with the blade lightly tapping the casing... ARRG...

Anyway, back to the clock, besides allowing sync to get down to sample accuracy, you must have the master clock to keep digital to digital transfers locked. Oherwise if the two independent clocks drift you will get digital "noise" and problems during the transfer such as digital artifiacts, pops, clicks, etc.
Basically the digital sample points drift of of sync and bamo... a click or worse...


[This message has been edited by georgia (edited February 19, 2000).]

[Arno Peeters]

georgia & peter ?
To be absolutely sure: having a (blackburst) masterclock would only be necessary if you have a mechanical device you need to sync to (i.e. tape) or if you have more digital channels than just one or two to route (all having a clock of their own)..

I've been using quicktime to spot my audio and lay it back on DAT: the actual master (beta) is made elsewhere... Never heard any complaints....
Should I expect any ?

your help is really appreciated !

(btw. georgia: 'had the thing you described happen to me some day: missed out a footstep or two in an animation that missed some frames....)

[This message has been edited by Arno Peeters (edited February 19, 2000).]

[Peter Steinbach]

Arno-
One last question...are you laying back to a timecode DAT? Also, when you layback to DAT, do you punch in near when the cue starts, or do you run the tape for the whole show/reel?
<<this is more than just one question>>
The reason I ask is this: Before I had a blackburst, and would layback effects for a commercial, I never had to worry about being in 100% absolute phase lock sync. The drift of the various clocks is not really a concern for 30 seconds. Now, if you're on a film with 8 minute reels, and you are laying back effects in uninterrupted 8 minute segments, SMPTE alone does not ensure absolute sync, hence the need for video sync.
Aside from the DAT issue, your sync situation sounds good.
BTW, I strongly reccommend the book "Timecode: A User's Guide". It answered a lot of questions for me. You can get it at Amazon.com
-ps



[This message has been edited by Peter Steinbach (edited February 20, 2000).]