View Full Version : Solid Keying Footage

06-02-2009, 04:17 PM
To those who are experienced with this kind of material, is it possible to shoot solid 720 footage for this purpose for those who've gotten their hands on camera?

Jackson Miller
06-12-2009, 03:58 AM
You mean color keying? I am also wondering. I have an upcoming project that I am planning on shooting with a GH-1 and there are two greenscreen shots. I hope the green of the greenscreen doesn't look the way some of the green trees etc. if footage I have seen so far. But anyone know if greenscreening is *doable with acceptable results with a GH-1? And if so would 720/60p or the MJPEG 30p work best? I won't probably be using the 1080/24p much at all unless there is a firmware update.

Thanks in advance.

06-13-2009, 10:00 PM
As with everything GH1: it should be fine if you don't have much movement...especially camera movement. Then again unless you're doing motion tracking and all that jazz you don't want camera movement in your greenscreen shots anyway.

Jackson Miller
06-13-2009, 11:56 PM
Haha. My shoot is a car hitting a person. So quite a lot of movement. But I'll be using 720p and have some other cams as backup. We'll see.

Martti Ekstrand
06-14-2009, 12:17 AM
Typically when you make greenscreen shots you don't want a shallow DoF so for those takes a small chip camera's deep DoF works to a advantage - for once. To top it off since you are most likely in a studio for those takes get a cam with full live video out and capture uncompressed with a computer. If you must do it with GH1 I'd guess the mjpeg would be better, haven't had time to do any key tests with either format though.

06-14-2009, 05:30 AM
thats odd.. i always thought a shallow dof was beneficial to green screen stuff..as if the screen is out of focus compared to the talent it hides creases , marks , col and light differences of the green screen....

have to say i am very interested in seeing what the GH1 is capable of in relation to keying....

Martti Ekstrand
06-14-2009, 08:24 AM
Well getting the screen slightly out of focus is a bonus but it should be clean and lit well enough to be keyed evenly even when focused. Not having the talent in focus all the way through creates extra work dealing with soft matte edges, especially hair can look weird. A typical overtime situation is a none-to-technical rock video director doubling as DOP placing a band infront of a screen with the singer in focus and the band blurred behind :)
And if you do camera moves that need to be 3D tracked the compositor usually prefer having the track marks on the screen in decent focus to ensure stable tracking.

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06-16-2009, 09:41 AM
You want to shoot as much color info as possible for chroma keying; ideally 4:4:4, if not then at least 4:2:2. In a studio you should have enough control to be able to shoot a small chip camera and still have the screen be slightly soft.

Jean Dantes
06-16-2009, 12:22 PM
720P is fine. 50P is also good, the more frames, the better for special-fx. Keep everything in focus, including the green-screen, do not use a shallow depth of field. The shaper the green-screen is in focus, the easier you will be able to key it out. Good luck!