chelgrian Posted June 16, 2013 Share Posted June 16, 2013 Often I have to put a conductor somewhere not directly visible to the stage requiring conductor relay via video. With CRTs and analogue output box cameras and composite video the latency wasn't noticeable. However these days LCD displays have to scale the SD video up introducing enough input lag (often over 100ms) to cause issues. In order to reduce lag removing the need to scale the signal so capturing and distributing it at 1920x1080 seems like the first step however cameras with HD-SDI outputs and HD-SDI capable displays are extremely expensive due to being designed for the low volume broadcast and film market. Ideally the end to end latency would be no more than 1 frame at 25p so 40ms. So the question is is there any economical way to do this or am I stuck with SD analogue box cams, composite video and used CRT monitors from ebay? Link to comment Share on other sites More sharing options...
paulears Posted June 16, 2013 Share Posted June 16, 2013 I think you probably are. Anything with HD conversion and back is horrible. I was in the gallery at one of the ITV centres with big screens instead of lots of small monitors and the lag was noticeable. Would a small CCTV camera and flat screen monitor not be the best solution? Link to comment Share on other sites More sharing options...
chelgrian Posted June 16, 2013 Author Share Posted June 16, 2013 I think you probably are. Anything with HD conversion and back is horrible. I was in the gallery at one of the ITV centres with big screens instead of lots of small monitors and the lag was noticeable. Would a small CCTV camera and flat screen monitor not be the best solution? The current solution involves cameras like: http://business.panasonic.co.uk/professional-camera/static-cameras/wv-cp500 Composite video distribution which is as cheap as chips and mostly unbranded and monitors like http://www.ebay.co.uk/itm/Sony-Trinitron-14-Broadcast-CCTV-Colour-Video-Monitor-PVM-14N6E-Free-P-P/290930728725?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D74%26meid%3D8421399505722521187%26pid%3D100005%26prg%3D1152%26rk%3D2%26sd%3D111003757189%26 the trouble with flat screen monitors is that they have to scale the composite input to the native resolution of the panel and most of them apply some processing at the same time. This pushes the input latency of the panel itself to unacceptable levels. Link to comment Share on other sites More sharing options...
GridGirl Posted June 17, 2013 Share Posted June 17, 2013 Sydney Opera House still uses CCTV cameras and CRTs for all mission-critical conductor cam. There are a lot of flat screen monitors throughout the building, but not where lag would matter (percussion section (they can't see the conductor all the time), backstage musicians, backstage singers etc etc). Link to comment Share on other sites More sharing options...
Brian Posted June 17, 2013 Share Posted June 17, 2013 This pushes the input latency of the panel itself to unacceptable levels. Mic the whole orchestra and then delay the sound to fit the video. Link to comment Share on other sites More sharing options...
Robin D Posted June 17, 2013 Share Posted June 17, 2013 Have you thought about using the original low tech solution - well placed mirror or two? Will not work all the time I know but might be worth considering. Link to comment Share on other sites More sharing options...
chelgrian Posted June 17, 2013 Author Share Posted June 17, 2013 Have you thought about using the original low tech solution - well placed mirror or two? Will not work all the time I know but might be worth considering. Unfortunately the most common situation is the the band are in an entirely separate room. This pushes the input latency of the panel itself to unacceptable levels. Mic the whole orchestra and then delay the sound to fit the video. That would produce some very weird effects because you also have vocal relay going back in the other direction and that is necessarily going to contain some bleed through from the delayed orchestra coming out of the PA so in the conductor's fold back you'd end up with a noticeably delayed version of the direct sound he's got in front of him. At best it would be horribly confusing at worst all the musos would up and walk out :) Link to comment Share on other sites More sharing options...
dbuckley Posted June 18, 2013 Share Posted June 18, 2013 ... at worst all the musos would up and walk out :) Look on the bright side: that's the latency problem sorted :) Link to comment Share on other sites More sharing options...
GR1 Posted June 18, 2013 Share Posted June 18, 2013 I agree with GridGirl. Use old fashioned analogue kit that doesn't process the signal but just pushes it onto the screen. Don't throw out working CRT screens - keep them for these jobs. Link to comment Share on other sites More sharing options...
dbuckley Posted June 18, 2013 Share Posted June 18, 2013 In the garage behind the theatre I have half a dozen ex-cctv tellies, kept knowing one day they would be needed... Link to comment Share on other sites More sharing options...
Bryson Posted June 18, 2013 Share Posted June 18, 2013 This list might be useful. 32"/40" TVs with lowish latency. It's meant for gamers but might help in your situation. This one is as low as 14ms. Is that low enough? (Assuming, of course, they still make those models. TV models turn over ever so quickly these days.) Link to comment Share on other sites More sharing options...
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