Monthly Archives: April 2009

Using Video in a Theatrical Application

A Reader Asks

“I’m debating using projections or a series of stacked televisions for an upcoming theatrical production.  I’m picturing a tower of televisions of multiple sizes on either side of the stage. The images on the televisions would be the same.  Nothing fancy like an image traveling down from the top to the bottom or one image being stretched over multiple televisions.
Initial thoughts: They are all daisy chained together and hooked to a single DVD or VCR.  But, how do you control them if there are periods where they wouldn’t be used?”

What you are describing is a pretty common setup. I would not recommend simply turning your video monitors on and off because some televisions will reset to a default state if they are disconnected from power and that default state might not be what you want it to wake-up in. What you need is a vertical interval video switch and a black burst generator. These devices will send black video to mute the screen when not in use. You also may want to mute the sound too. A solution for this would be a vertical interval “Audio Follow Video” switch. All “vertical interval” means is that it will switch your video seamlessly without a big break-up (glitch) on the screens.  
As far as interconnection, when you are sending the same source signal to all the video monitors it is seldom a good idea to “Daisy-Chain” an audio or video signal, especially when it comes from a relatively weak source device like a consumer DVD or VCR. I strongly recommend a device called a Video Distribution Amplifier. You also would need an Audio Distribution Amplifier if you are going to send the same audio to all the television monitors.  
I know you said you had a single source but if you wanted to send a different signal to all the monitors or do fancy images that would go from a different picture on every screen to a big blow up of a single image using all the screens there is a solution for that too. You could get software driven system that would do this automatically for you. They are expensive but rentable at a fairly reasonable cost if you are a one and done kind of user. -33-