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Gary Randall April 2nd, 2009 02:24 PM

Background
 
I just shot my pastor talking and I want to put an alternative image behind him. (like a book case or Fireplace) Can I do that in Vegas? if not, can you tell where I get get software to do that? Easy if possible. I am a newbie

Thanks
Gary

Stan Harkleroad April 2nd, 2009 03:00 PM

He needs to be shot in front of a solid color screen to do this. Green is typical with digital video. Then you cna use the Chroma Key function in Vegas.

Gary Randall April 3rd, 2009 06:26 AM

Stan, Can you explain how to do that. I tried, but can't seem to do it.

Thanks
Gary

Edward Troxel April 3rd, 2009 06:50 AM

Gary, you simply need to put the green screen video on track 1 and the new background on track 2. Then add the Chroma Key effect on the track 1 footage and adjust it as needed to key out the green.

Gary Randall April 3rd, 2009 07:06 AM

Great, Thanks Ed

Edward Troxel April 3rd, 2009 07:21 AM

One thing to note - getting a good chroma key can be an art unto itself. So you might also want to do a search on Chroma Key to see other tips on that particular task. But the method I gave is the bare basics.

Michael Hazzard April 3rd, 2009 08:22 AM

As someone else was is inexperienced with, I can attest it is a tricky task. My best results to date have occurred when the green background was very well lit. Seeminlgy even more important than the subject lighting.

Don Bloom April 3rd, 2009 08:53 AM

green screen not only needs to be lit well and evenly but the lighting on the subject needs to be properly done so as not to cast any kind of shadow or fall off light on the background.
If these 2 things are done a great many headaches of chromakeying are not in play. When setting up the subject make sure they are far enough off the background so the 2 lighing can work independently of one another-I've found typically 6 feet is the minimum but it varies depending on the framing of the shot.

Renton Maclachlan April 3rd, 2009 03:09 PM

I've just been improving my green screen setup in prep for a bit of shooting.

I'm using the 2.7m wide green screen paper on a roll which I drop down from the roll fixed at ceiling height, onto the floor (when I'm using the room as a studio).

I have just set up four banks of 1.2m double flourescent lights, two shining down on the screen from above - the full wideth of the screen, and two shining up from the floor. I've made custom built light shades for these so that all light goes towards the screen. The lights are about 1.2m in front of the screen - I had them closer but slight shadows were cast on the screen, so moved them back.

The lights alone were too bright for the screen and seriously affected the camera readings. Also the brighter the screen, the more reflected spill onto the subject is possible.) To reduce the brightness I have put paper filters over the lights (from a 1.2m roll of paper I had kicking around) and this has worked brilliantly. I have one layer over the top lights and two over the bottom ones. For some reason the bottom ones were putting more light on the screen.

Recommend distance of subject from screen is 3m, though I can't quite get that. Light functions in accord with the inverse square law so doubling the distance from the screen reduces the reflected spill by four.

Any spill can be minimised also by the backlight - having it brighter presumably will lessen the effect of spill. I've also read the suggestion that putting a magenta filter on the backlight will neutralise any spill from a green screen seeing magenta is greens complimentary colour. I haven't yet tried that.

I'm using a 12in LCD screen to monitor myself as the subject as I set up my cameras and also as I do my presentation - to make sure I stay properly in the screen. I have set this up on top of my teleprompter (homemade - in a box) and just twigged onto the fact that if I had this running colour, I could get a green reflection back onto the subject from the monitor. By getting rid of the colour - switching to black and white, I get rid of that possibility. As I mentioned in another thread I started re this topic, I'm going to be shooting three cameras through the teleprompter, each with a different setting.


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