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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Pro AV Forum => Topic started by: John L Nobile on February 10, 2015, 02:36:28 pm

Title: Camera on drummer with screen behind him
Post by: John L Nobile on February 10, 2015, 02:36:28 pm
I want to shoot a drummer (figuratively) who will be sitting in front of the screen that he will be projected on. The camera will be shooting it's own image as it's projected in real time.
I've never done this but will that cause any video feedback issues?
Title: Re: Camera on drummer with screen behind him
Post by: Chris Clark on February 10, 2015, 06:16:44 pm
Depending on how close to the drummer the camera would be, could you "mask" behind him/her (basically a backdrop that would make the back of the video that instead)?

Although in all reality I'm presuming the screen would be much larger than the drummer, so in reality you'd only pick up a small fraction of the "infinite loop" I'm sure we all played with at one time in our lives. I've seen it done before and don't think it would be a huge issue.
Title: Re: Camera on drummer with screen behind him
Post by: Jonathan Kok on February 11, 2015, 11:02:10 am
No 'feedback' other than the infinite loop. Note that due to video processing delay, the 'further' images will lag behind the 'closer' images.
Title: Re: Camera on drummer with screen behind him
Post by: John L Nobile on February 11, 2015, 11:21:08 am
What is the "infinite loop" and how will affect the image?  I did a google search but that was useless.

This won't be happening till April but I wanted to research it first. I'm a video novice. The screen is 200" diag and will right behind him.
Title: Re: Camera on drummer with screen behind him
Post by: Mark Olsen on February 11, 2015, 02:21:39 pm
What is the "infinite loop" and how will affect the image?  I did a google search but that was useless.

http://en.wikipedia.org/wiki/Video_feedback
Title: Re: Camera on drummer with screen behind him
Post by: John L Nobile on February 11, 2015, 02:45:28 pm
Thanks for that link. I wanted to make sure that there's no damage done to the gear.I guess I'll have to do it to see what the actual effect is. Might be interesting for the obligatory drum solo.
Title: Re: Camera on drummer with screen behind him
Post by: Scott Holtzman on February 11, 2015, 03:07:12 pm
I want to shoot a drummer (figuratively) who will be sitting in front of the screen that he will be projected on. The camera will be shooting it's own image as it's projected in real time.
I've never done this but will that cause any video feedback issues?

I don't know anything about your switcher but I do know years ago the Intergroup Switcher at a Trinity station (circa 1992) was able to edge out feedback pixels and background blend.  Very similar to a chroma keyer.

Title: Re: Camera on drummer with screen behind him
Post by: John L Nobile on February 11, 2015, 03:18:09 pm
I don't know anything about your switcher but I do know years ago the Intergroup Switcher at a Trinity station (circa 1992) was able to edge out feedback pixels and background blend.  Very similar to a chroma keyer.

I don't have a clue what you're talking about lol

Guess I'm going to have to educate myself if I'm going to use any video in our next show. But just enough to stay out of trouble.
Title: Re: Camera on drummer with screen behind him
Post by: TJ (Tom) Cornish on February 11, 2015, 03:26:49 pm
I want to shoot a drummer (figuratively) who will be sitting in front of the screen that he will be projected on. The camera will be shooting it's own image as it's projected in real time.
I've never done this but will that cause any video feedback issues?
You won't damage video gear with video "feedback", you just get the infinite tunnel effect.  I agree with the others - that's probably unsightly enough to try to either figure out camera angles that won't hit the screen or put something behind the kit to block it.
Title: Re: Camera on drummer with screen behind him
Post by: Scott Holtzman on February 13, 2015, 02:55:59 am
You won't damage video gear with video "feedback", you just get the infinite tunnel effect.  I agree with the others - that's probably unsightly enough to try to either figure out camera angles that won't hit the screen or put something behind the kit to block it.

The switcher is the device or software that selects the video signal output to the displays.  It is also where transition effects, titling etc. is done.  Chroma keying is the technique used in weather broadcasts and movie special effects to superimpose backgrounds.
Title: Re: Camera on drummer with screen behind him
Post by: John L Nobile on February 13, 2015, 09:05:27 am
The switcher is the device or software that selects the video signal output to the displays.  It is also where transition effects, titling etc. is done.  Chroma keying is the technique used in weather broadcasts and movie special effects to superimpose backgrounds.

Thanks for explaining that Scott. This site is actually a classroom disguised as a forum.