my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Equipment for adjusting A/V sync (Page 2)

This topic comprises 2 pages: 1  2

Author Topic: Equipment for adjusting A/V sync Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 01-02-2017 01:08 PM                     The leaders of most films had both numbers in a frame as well as a diamond in another frame. A letter from the film company supplying "The Godfather" version #1 stated that the projector was to be loaded with the number frame in the gate in front of the lens and the corresponding diamond was to be at the light slit of the sound reader. These leaders were printed with the standard offset being the distance from the number frame to the corresponding diamond. The sound was very hard to understand on that film as Marlin Brando spoke very softly. (There was a theme song for that film also. The title was "Speak Softly Love")  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-02-2017 01:51 PM                     I used to have a Tech print of that and #2, and I don't remember there being any intelligibility issues with it or #2. Mark  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 01-02-2017 03:08 PM                     Mark, Does your print of #1 have the lab test inserted into the opening credits? There should be a splice there is it was removed. I got a call from Hollywood to take the film out of the projector and remove the "watermelon girl" strip as someone at the lab thought it was just in a blank spot in the leader.  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 01-02-2017 04:54 PM                     quote: Scott Norwood Surely, one would need to adjust sync differently at Radio City than in a small screening room True- - fortunately, in the case I mentioned in my post, I'm only dealing with a room that seats 80 people, so it isn't large enough for there to be any noticeable sound delay from the front to the rear. But if a DCP's sync is "off" it's noticeable everywhere in the room. I usually stand just short of the center of the room when I need to check or adjust the sync. Oddly enough, due to some quirk in the way the system is wired, changing the audio delay in the auditorium to anything other than the 'normal' setting, doesn't change the delay to the booth monitor speakers. So even if I 'fix' sync in the auditorium, it still looks out of sync in the booth, which is very annoying to me if I'm trying to watch the flick from there. Thankfully, it's a situation that doesn't happen too often. As for Radio City- - I grew up in NY, so I've been there many times. Great theater, but to me, the auditorium architecture always made me feel like I was watching a show while sitting inside a giant armadillo.  |  IP: Logged Kristo Nalo Film Handler Posts: 24 From: Skopje, MK, MK, Macedonia Registered: Nov 2016 posted 01-03-2017 06:34 AM                     I don't have any experience about that before. Hope someone can give you a good advice.  |  IP: Logged Mattias Mattsson Film Handler Posts: 90 From: Göteborg, Sweden Registered: May 2007 posted 01-03-2017 03:55 PM                     Thanks all for your insights! The Sync-One2 seems really promising but I don't find any sync test DCP:s on their site. Pete, do you know if they provide any for use with their meter?  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 01-03-2017 04:45 PM                     Hi Mattias, you need to create your own Test-DCPs from these files: http://www.sync-one2.co.uk/support/test-files/ Simple procedure, did you ever try DCP-o-matic? - Carsten  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 01-04-2017 02:47 AM                     Mattias, Carsten has it covered, you can self convert, or use one of the many readily available DCPs. The syncone2 only needs to see a flash and hear a blip. That said, the designer is keen to have DCPa available, he has an update to the test file section scheduled soon, so they may appear then. I am fortunate in that I have a Clipster near me where I can get the odd small favour DCP Jon done, I got the test files converted there.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-04-2017 05:59 AM                     I've been quite happy with the DCP created here: http://www.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=001037#000009 It should work with any of the systems that look for a flash and the "crack" of the sound. It would seem to me that the cell phone based systems could be reasonably easily calibrated by merely making your own test by using a clapper or dropping a book on a table and then measuring that sync and therefore have your phone's offset. You only really need to be accurate enough for the frame resolution you are working with. In A/V systems, I rarely offer lip sync adjustments in msec. Instead I tend to move in frame sized hunks. If there is a lip sync problem, you want to move quickly to the point where it appears correct. As others have noted, depending on the workflow of the material, the sync could vary throughout the performance. Even back in 2003, this is a screen shot of the "home" screen on one of the AFI's portal touchpanels http://www.film-tech.com/warehouse/picview.php?id=4770&category=1. While looking out of the port, the projectionist can move between 0 and 4 frames of delay, as needed. In truth, the delay was a fixed amount per frame (it didn't know if you were running 24fps or 60fps) however, within seconds the operator could resolve such an issue because you do not need precision as a little too much will always appear better than too little.  |  IP: Logged Jeffry L. Johnson Jedi Master Film Handler Posts: 809 From: Cleveland, Ohio, USA Registered: Apr 2000 posted 01-12-2017 01:27 PM                        SMPTE 40 3 Longitudinal picture-audio displacement 3.1 The audio record on the film shall be displaced longitudinally from the center of the corresponding picture by a distance of 21 frames ± 1/2 frame in the direction of film travel during normal projection. 3.2 Although picture and audio are correctly synchronized with a displacement of 21 frames ± 1/2 frame on the film, normal playback of motion pictures occurs in theaters where the relatively slow speed of sound means that the audio should precede the picture at the screen if subjectively correct synchronism is to be achieved in the middle of the theater (see annex A). Annex A (informative) Explanatory notes In the average theater, it is necessary to emit the sound pulses before the corresponding picture frame is positioned in the aperture. Since sound travels approximately 1100 ft per second or about 50 ft per frame during the normal projection rate of 24 frames per second, the projectionist can place the sound and picture in synchronization in the theater where he wishes by varying the length of the threading path in the projector. For example, if the positioning of frame 21 at the scanning point brings the corresponding picture and sound to the screen and the speaker at the same instant, then positioning frame 20 at the scanning point would give synchronism at about 50 ft from the screen.  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

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.