Film-Tech Forum ARCHIVE: Release Print Sound Track Printing

This is topic Release Print Sound Track Printing in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jim Cassedy (Member # 4115) on 08-19-2008, 09:55 AM:

It's been many years since I worked in a film lab.
I'm curious about how all the 'new' sound-tracks are printed.

1) Is the DTS timecode part of the optical sound track negative, or is it a seperate negative?

2)Does the Dolby Digital track come from a negative or is it exposed individually on each release print from some sort of track printer with a photodiode array?

3)Same Question for SDDS.

Thanks

Posted by Richard Fowler (Member # 893) on 08-19-2008, 10:06 AM:

Generally they 4 in 1 negatives. DTS module is generally within the Westrex sound camera and SDDS us usually a penthouse mounted to the recorder. DTS tracks can be laser burned on to existing prints for specialized use, such a print for an archive.

Posted by Leo Enticknap (Member # 534) on 08-20-2008, 04:57 AM:

Didn't know that DTS timecodes could be burnt directly onto processed release prints. Is the error rate as low as properly printed ones? What does the cost per print work out at (for example, if you're doing a small run of, say, 3-5 prints of an arthouse title, would it be cheaper to burn the DTS timecodes rather than prepare a track neg with them?)? Is the technology used to burn them essentially the same as for laser subtitling?

Many thanks in advance...

Posted by Richard Fowler (Member # 893) on 08-20-2008, 07:20 AM:

While working with a film archive in Latin America, they where looking for a way for syncing more accurately projected sub-titles. They where using a shaft encoder and where in the mercy of print length and threading issues. DTS at the time had a service for sub-titles and said they had the capabilty of making tracks on existing prints with a German recorder which I think was from MWA......this was 10 years ago.

Posted by Jack Theakston (Member # 4484) on 08-20-2008, 03:23 PM:

I would think that laser-etching the DTS track would have a fairly high error rate, as the placement of the information has to be fairly precise, at least by DTS's own standards.

Posted by Leo Enticknap (Member # 534) on 08-20-2008, 05:10 PM:

That was exactly what occurred to me, too: the edges of the letters in laser-burnt subtitles look a lot rougher than a printed DTS timecode. Presumably the DTS data blocks are large enough for the reader to be able to cope with laser-etched ones. If so, that shows just how resilient DTS is: if the readers can cope with that, I'm sure they can cope with a level of dirt and scratching on a typical release print that would cause Dolby to fail.

MWA are some seriously smart cookies. I had the privilege of visiting their factory in Charlottenburg (a suburb of Berlin) for the training session on a small gauge telecine which the archive I used to work for bought a couple of years ago. Amazingly, they build their line of mag followers, LCD/CCD based telecines and laser film recorders from the ground up in a tiny factory sandwiched between two blocks of flats in a residential side-street off the main road from Berlin city centre to Tegel Airport. Everything form machine tooling the chassis and mechanical film path components to assembling the circuit boards happens there. I've never used their film recording products, but their Flashscan and FlashTransfer telecines are very innovative technologies, delivering true broadcast quality for about 15% of the cost of a Cintel or a Spirit. If they have found a way of directly burning a digital audio track or DTS timecode onto a projection print, this strikes me as precisely the sort of niche market they would try to develop and make cost effective, which the bigger players would give up as being not worth the bother.

Posted by John Hawkinson (Member # 1135) on 08-20-2008, 09:45 PM:

I don't see any reason to think there would be a high error rate. It's possible to be extremely exact and DTS has the advantage that the laser never has to move horizontally, it can be precisely aligned in the lateral dimension and then it's good-to-go.

But even if the process were error-prone, then they'd just slow down the machine until it was stable. So it might be slow, but it'd work fine.

But again, I don't think there's any reason to expect it can't run fast without errors. It's a pretty well-defined task with clear parameters. And it doesn't matter if the edges of the laser are fuzzy, as it might with subtitles. The DTS reader reads in one dimension only.

Honestly, the only real fear is that the track might be big enough to break into either the picture area or the analog soundtrack. But that's wild unfounded speculation. I doubt these problems exist.

--jhawk

Posted by Paul H. Rayton (Member # 1817) on 08-24-2008, 08:13 PM:

As Mr. Spock would have said on Star Trek, "Fascinating". If this (creating DTS timecoding after development) is true, it would mean that a few of the recently-struck 70mm prints that were produced minus any timecoding could now be coded and shown, without the expense of doing it double-system. There are new (or new-ish) 70mm prints of "Ryan's Daughter" and "Grand Prix" (and possibly others) which could thus be showable...

Posted by Carl Martin (Member # 1146) on 08-25-2008, 01:25 PM:

were they created without dts or mag striping? if striped, the laser would have to penetrate that (from the opposite side). i wonder how bad the effect would be on the mag sound. if not striped, the edge would still have to be black.

also, 70mm timecode is wider than that on 35mm, but that's probably for robustness's sake and not strictly necessary.