Green screen backdrop questions
by Norman Willis
on
Jul 7, 2009 at 7:51:50 pm
Hello. A friend of mine (in another country) is taking some footage as a backdrop for some green screen work. If I have a long teaching video (maybe two hours) that has a green screen background, about how much footage do I need of the backdrop?
If the camera cuts away from the talent (onto other screens) and then back every minute or so, can I just have my friend take one good fifteen minute clip, and then butt them together for the two hour length? Or will it be obvious that I am using the same fifteen minute clip over and over again?
Does Vegas have any preferences with regards to background footage length for green screen?
Re: Green screen backdrop questions by John Rofrano on Jul 7, 2009 at 8:30:01 pm
It depends on what the backdrop is. If it's a city street and the same people walk by every 15 minutes it might be noticeable after the 3rd or 4th time. If it's the ocean, I doubt someone will recognize the same wave after 15 minutes. ;-)
Re: Green screen backdrop questions by Norman Willis on Jul 7, 2009 at 8:45:06 pm
So if it is an ancient stone wall, probably no one will notice unless there is rolling cloud cover, or unless we get birds dive-bombing the camera? (Which I have seen....)
Re: Green screen backdrop questions by John Rofrano on Jul 7, 2009 at 9:13:13 pm
Fixing the rolling cloud cover is easy. You can make most backdrops a continuous loop by splitting them in the middle and swapping the left and right halves (so that the inner split which is guaranteed to match is now at the left and right end), and then overlapping the two events by a few seconds in the middle. This will make the ends blend seamlessly and the backdrop now loops forever.
Re: Green screen backdrop questions by Danny Hays on Jul 7, 2009 at 9:30:43 pm
Another option is to use the audio only for the clips without the green background and use other video or screen shot pics, what ever you have thats relevent to the movie for the background for those sections. I really love Sony Vegas but the chromakeyer isn't very good. If your shooting DV, try putting a chromablur, set to medium before the chromakey pluggin in the chain. It really helps minimize the jagged edges commonly found when keying DV footage due to the 4.1.1 color space. check out this video on this subject on my You Tube channel. Most of my vids we're shot in front of a green screen but with an HDV camera. I didn't use Vegas for the chromakeying, I used Ultra 2.
Re: Green screen backdrop questions by Norman Willis on Jul 7, 2009 at 11:36:08 pm
Hi Danny.
Great vid. Very illustrative. Makes the point fast.
I don't have budget for CS4 at the moment, but want to move that way. I love Vegas also, but my only frustration is that they seem to be intent upon keeping it a 'mid-price-level' product (at the expense of functionality), in order to keep it affordable.
Affordability is great, but why not make a true mid-level version ("Sony Vegas Hobbyist"), and let VPro really be pro? Everyone says it is the NLE of the future, so why not make it that way today, and take over the industry?
(OK, enough ranting.)
The only other keyer I've got is Boris RED (long story), if I can get it to work on Vista 64. It might, since I don't have Adobe CS Anything installed; but I have not worked with Boris yet, and don't know how good of a keyer RED is.
I assume Ultra is better, because that seems to be what everyone here uses.
Norman Willis
www.nazareneisrael.org
servant@nazareneisrael.org
