Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » SDDS Drop-out

   
Author Topic: SDDS Drop-out
Ken Lackner
Phenomenal Film Handler

Posts: 1907
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 11-24-2001 02:20 PM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
Do both SDDS tracks contain the same info, or are they different? If you use the kind of cue tape that you fold over the edge of the film, or if you use CPI's edge marking tape, you will be completely covering the SDDS S-track. How long until the SDDS drops out?

(Dolby Digital is 4 data blocks before it drops out, right?)

 |  IP: Logged

Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 11-24-2001 02:41 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I've used a 1 inch (5 perf) piece of white Artist's tape across the entire frame to make a splice with (not for a real show, just to prove a point) and had no dropout in SRD or SDDS. I don't know what the limit it, but if your readers are lined up properly, there shouldn't be a problem.

 |  IP: Logged

Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001


 - posted 11-24-2001 06:48 PM      Profile for Bobby Henderson   Email Bobby Henderson   Send New Private Message       Edit/Delete Post 
Both Dolby Digital and SDDS can miss up to four frames worth of data before faulting out to the analog track (or in SDDS' case, the half-quality digital track and then analog track). Both systems have a lot of data redundancy built into their tracks. Dolby Digital for instance operates at 320kb/s, but there is actually 556kb/s worth of data being read every 24 frames. The primary digital track for SDDS operates at 1.2 million bits per second, but a full 2.2 million bits of data are printed every 24 frames.

Still, it is a good idea to make those splices as clean as possible since you never really know just what portions of backup data are being eliminated in between splices.

 |  IP: Logged

Richard Topping
Film Handler

Posts: 13
From: Newcastle-upon-Tyne, UK
Registered: May 2001


 - posted 11-25-2001 01:04 PM      Profile for Richard Topping   Author's Homepage   Email Richard Topping   Send New Private Message       Edit/Delete Post 
SDDS has differant info' printed on the 2 sides. Soundtrack Side has Centre, Left Centre, Left and Left surrounds as well as a back-up track which is a mix of the Right Side in case's of DCM (digital concealment mode)). The Picture Side has Sub, Right Centre, Right and Right Surrounds as well as a back-up track which is a mix of the left side. The 2 tracks are printed 17.3 frames away from each other.

I usually only cover 3 perfs on emulsion side for a reel marker, but have known both tracks to be covered without any drop out.

 |  IP: Logged

John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 11-26-2001 12:03 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
I recall there was a thread on this very subject in July 2001. Al Barton of Sony joined the discussion, and offered to have his technical people answer specific questions.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

 |  IP: Logged

Ken Lackner
Phenomenal Film Handler

Posts: 1907
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 11-26-2001 12:51 PM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
Thanks, John. Was that the thread entitled "SDDS backup track defeat"? Too much technical info that was over my head! I simply want to know that if I use cue tape or CPI's edge marking tape, will it affect SDDS?

 |  IP: Logged

James R. Hammonds, Jr
Jedi Master Film Handler

Posts: 931
From: Houston, TX, USA
Registered: Nov 2000


 - posted 11-26-2001 08:11 PM      Profile for James R. Hammonds, Jr   Email James R. Hammonds, Jr   Send New Private Message       Edit/Delete Post 
No, it shouldnt.
I use cues all the time that fold over the edge with no problem.
Also,b back in my days of solid yellow splicing tape there were no dropouts.

 |  IP: Logged

Ken Lackner
Phenomenal Film Handler

Posts: 1907
From: Atlanta, GA, USA
Registered: Sep 2001


 - posted 11-26-2001 10:31 PM      Profile for Ken Lackner   Email Ken Lackner   Send New Private Message       Edit/Delete Post 
Thanks, that's all I needed to know

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.