Film-Tech Forum ARCHIVE: DTS 70mm Timecode

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Posted by Ben Wales (Member # 92) on 11-13-1999, 06:04 PM:

The venue I work at has produced a 70mm film (I will not say where at the moment)which carries a DTS 70mm timecode signal, it runs for about 33mins, so the print is made up of two reels, the timecode is converted through a DTS timecode to a standard SMPTE timecode converter to run the sound in sync of a 8 track hard drive system, it has been found that on reel changes the film goes way out of sync.

I explain below.

1)On the end of reel one, the DTS timecode resets to reel two, and resets SMPTE timecode clock to zero.

2)The 8 track hard disk drive system can locate the second part of the film track, but as soon as it picks up the new SMPTE timecode the system is about two seconds out of sync on reel two, ie it's reset time is too slow!.

3)The present options available,is to rewrite the software for the hard drive unit, for a quicker pick up rate when reading timecode.

b)Reprint a complete new 65mm inter neg and new 70mm prints with a revised DTS timecode track, clocked to show it as only one reel, but I understand the labs can only print up to 20mins per reel for 70mm, this may be a costly option, but may be practical.

3) We do have the sound track on a standard DTS disk, which works well, and ideally we should play the film sound track of this than messing about with a hard drive system not designed for this!.

4)Is it possible to just run the film timecode signal from it's DTS disk from a computer or DTS player connected through a DTS timecode generator to the converter?, rather than running the print each time.
We want to simulate a reel change on the test bench to the hard drive system to see if the hard drive disk system can reset quicker.

I would welcome any suggestions how we could resolve this problem.

Posted by Brad Miller (Member # 2) on 11-13-1999, 06:45 PM:

I vote for option #3! The DTS70 system works, and works very well. Why screw around with an external hard drive system??? If you're just dead set on 8 channels, why not chain 2 DTS units together and get 10.1 channel sound? To hell with EX, you could have discrete QUAD surrounds!

DTS does make a timecode generator, but I'm not sure of what all it is able to do (aka simulated changeover). Might want to contact them.

Posted by Scott Ribbens (Member # 180) on 11-13-1999, 07:49 PM:

I own a DTS portable timecode generator, and here is what it can and cannot do. It can simulate the timecode for any reel and any serial number, all you have to know is the serial number, enter it and run, you can even fast forward or back track through a reel.

What the timecode generator cannot know is how long a reel is. As a result, it just continues to generate timecode for the reel that you are simulating, until you enter a new reel number. To do this you hit a reset button, bring the cursor through the ser. # to the reel number, scroll the reel number up, hit arm, hit the position or increment button, then it send the ser. # and starts the timecode for the new reel.

If you are fast on the buttons, and know exactly where the first reel ends (footage wise) you can come very close to making a reel change with no drop in the sound. BTW the footage is displayed while the timecode is being generated.

------------------

Scott

Posted by Gordon McLeod (Member # 33) on 11-13-1999, 10:58 PM:

1 use the special venue DTS 8P which is a eight channel hard drive system
2 Put a shaft encoder on the projector and DTS make a BiPhase to timecode generator
All it cares about is where is reel 1 pix start and then the biphase clock
If the regualar DTS disks are used which have reel ID a foil sensor can restet the unit on each reel to frame1

Posted by Ben Wales (Member # 92) on 11-14-1999, 05:13 AM:

Yes, we do have a DTS timecode gen, but found to simulate reel changes were not ideal in this case.

We will check out this DTS 8P Hard Drive, no one at our local DTS office told us about this one.