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Author Topic: Roll Bars During Pre Show Martin McCaffery Film God Posts: 2481 From: Montgomery, AL Registered: Jun 99 posted 05-28-2013 08:55 AM                        Went to the AMC (formerly Rave) Festival Plaza to see Iron Man. While they continue the Rave tradition of dim projection, and this is the first commercial theatre showing where I've ever felt like asking them to raise the volume, the most annoying thing was during the pre-show advertising-a-thon (even more annoying than the advertising--at least 3 ads for television shows!). All through the pre-show, which appeared to be presented in 720, there were bars rolling up the screen. They weren't black bars, like on old TV's but regularly space "clear" bars, as if they were embossed on the image. What were these, what caused them and how can I avoid them when we get digital?  |  IP: Logged Harold Hallikainen Jedi Master Film Handler Posts: 906 From: Denver, CO, USA Registered: Aug 2009 posted 05-28-2013 09:09 AM                        Sounds like hum bars. They might be using analog video and have a ground loop. Harold  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 05-28-2013 11:29 AM                     Definitely sounds like a video-ground-loop problem as Harold said. quote: Martin McCaffery how can I avoid them when we get digital You should not have any problem when playing back digital content from your server, but hum-bars sometimes occur when interfacing analog equipment. (BluRay, DVD, etc) Most common way to fix it is to buy a "video-humbucker" box. They come in both active (opto-isolated) and transformer coupled versions, and sell for abt $50-$200 depending on type & quality. It's a good device to have on hand anyway. I have a semi-professional one with both RCA and BNC video connectors on it that I keep in my "bag of tricks". It cost me about $150(us), and is worth every penny. It has more than paid for itself by saving time, labor & head-banging when trying to track down vexing video ground loop problems while attempting to interface 'outside' equipment into our system. Since one of the facilities I work at is often used for corporate events, I've often got to hook "client provided" equipment into our system, so I've even got a "VGA Isolator" - which has cured a lot of problems when connecting up a client's computer to the system over a long cable for their power-point presentations, etc. Depending on the nature of your business and how much 'interconnecting' you'll be doing, you may or may not need any of this. But I've found the extra equpment to be a good investment in my particular projection situation. "I'm just sayin'......  |  IP: Logged Martin McCaffery Film God Posts: 2481 From: Montgomery, AL Registered: Jun 99 posted 05-29-2013 10:29 AM                        There will be much interconnecting in our future. Thanks for the info and tips.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 05-29-2013 08:56 PM                        quote: Martin McCaffery All through the pre-show, which appeared to be presented in 720 Highly doubtful. Probably 480p.  |  IP: Logged Martin McCaffery Film God Posts: 2481 From: Montgomery, AL Registered: Jun 99 posted 05-31-2013 08:01 PM                        Whichever, looked like crap.  |  IP: Logged

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