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- This topic has 6 replies, 1 voice, and was last updated 10 years, 9 months ago by Anonymous.
July 16, 2010 at 9:51 PM #47190AnonymousInactive
When I green screen anything, the subject always has a green outline around them. Any suggestions other than turning up the sililarity thingy. I do the best I can with lighting.
July 16, 2010 at 10:15 PM #194303RobParticipant
there’s isn’t really much room for error if you want a good key.
While shooting, make sure the chroma key is evenly lit. Also make sure there is a rim light around your subject, and try to keep your subject far away from the wall to avoid any color reflecting onto them.
It’s important not to record a highly compressed codec as well. DV, AVCHD, HDV, XDCam, H.264…all not very good for chroma key. DVCPro 50, DVCPro HD, Beta SP or DigiBeta, ProRes…all good for chroma key. Obviously, uncompressed is good too.
While in post, you should be able to feather the edge of your key, that may help if you’re stuck with what you have. And if you didn’t record one of the codecs that I listed for being good for keys, transcoding to them before doing your key may help
July 17, 2010 at 2:26 AM #194304XTR-91Participant
“…always has a… outline around them”
I’ve had the same problem now and again (actually all of the time) I try to use any form of chroma key. When I’m cutting around a photograph (adding green in Paint) and tried saving it in both Bitmap and JPEG formats, I’m always getting a green (or white outline), depending on the color chosen, even if I load a raw bitmap into editing software. This happens the same way in both Cyberlink PowerDirector and Sony Vegas Pro 9.
always happens no matter what I’ve tried or am using
July 17, 2010 at 3:28 AM #194305EarlCMember
As pointed out by Rob, the more compressed forms of digital are heck to get absolute and clean key. The rim, or hair, light can work wonders at times, at other times it makes no difference at all.
Ironically, ye olde S-Video, Hi8 even VHS stock made the creation of super clean keys doable. And, of course the higher, less or no compression digital formats.
Clean keying IS possible, but there will be instances where it simply cannot be as clean as you want for high end commercial work without going with better tools (cameras capable of the DVCPro 50, Beta SP, etc.) to acquire your footage with.
July 17, 2010 at 2:06 PM #194306Grinner HesterParticipant
Walk em away from the cyc as much as you can. A good back light cuts em out well.Depending on the keyer you are using you can correct the spill and tweek the edge as needed.
July 17, 2010 at 8:23 PM #194307D0nParticipant
with chroma keying, lighting your subject and your screen seperately is the trick…. striplights are your friend… set behind and aimed at 45 deg towards the subject you get nice clean separation, no spill.
this one done as a still image, but the lighting is exactly the same for video:
July 17, 2010 at 8:46 PM #194308D0nParticipant
interesting point Earl made about older formats….
I’ve been experimenting with filming some objects with my old Sony digital 8 (dv format) for insertion to avchd clips shot on my sr 12….
my reasoning was simply to speed up workflow by not shooting the objects I’m keying into the final hd clips in a higher resolution than needed since they’d only be small onscreen in the final clip.
those objects filmed in dv are keying very well…. and so far looking good in the final hd clips…
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