how do you key, your footage shot on ex-3
 

how do you key, your footage shot on ex-3? whats the best way to get a good key? just going uncompressed?

if not doing it uncompressed would using cineform Prospect 4K help at all? like if you just shot and then converted it to cineform

havent had to key yet. but you should visit the "nanoflash" forum
Convergent Design nanoFlash Forum at DVinfo.net
they have thier SDI HDMI recorder thing that records off the uncompressed output, in less compression with the ability for better color holding capability. one of the big advantages being green/blue screen type keying.

remember also that how badly something compresses is how much movement there is, and the resolution shot in and the codec and compression ratio. and progressive or interlace in these is a factor too. so talking heads or dancing gnomes will make a lot of difference when it comes to compression.

ONCE you have already compressed it the FIRST time, no greater codec/compressin will help you recover THAT loss, only the next losses and on and on, for all the times that you De-Re compress it again.

generally processing in the editing/effects/process programs is done on the signal after it is de-compressed, so decompressing ONCE in the programs processing/keying Will occur after that you could try and maintain what comes out the other end.
in the same sence, you have to decompress it and then RE-compress it to get it into a more lossless codec, possibly making things worse before you Need to do that.

I am no master at greenscreen but have keyed enough of my own footage to know a little.

The Nanoflash is a huge plus, just in general. For both the color sampling but especially the bitrate advantages. You could of course shoot into a AJA or Blackmagic equipped tower, but I haven't really wanted to do that myself. Shooting into a computer via SDI does allow you to use software like DV Garage Conduit 2 so that you can pull live keys.

Personally I don't like the standard Final Cut keyer, I think that Keylight 1.2 in After Effects is much better, and Key Correct Pro from Red Giant compliments Keylight well.

Good lighting is so important, and if you have a waveform monitor, by all means that would help.

As previously mentioned it also depends what you are keying. Sometimes it is pretty easy, you have a large subject that doesn't move fast. You can stick with 1/48 shutter speed and pull a nice clean key. I shot a spider on plexiglass a few months ago crawling over the camera and a blue screen about 6' above the spider. I shot that at either 1/125 or 1/250 sec, f/8. Those thin legs would never key with motion blur and you have to account for that and keeping what you want to key in focus by shooting a moderate aperture. I don't see myself shooting something I would want to key at something like f1.9 or 2.8. If you need to open up that much to get enough light for a decent exposure, add more light to the scene. We had to pop that spider pretty good to get our lighting levels to the point of our required shutter/aperture.

Anyway, I think you can do some pretty nice work even without shooting uncompressed or into a Nano, but that Nano is so useful it really does make sense.

I would use something like NeoHD to transcode that Nano footage over to Cineform 444, Filmscan 1 quality. That becomes your master and is a true intermediate codec that uses wavelet compression. Cineform isn't quite a RT codec yet, but they just released a version that supposedly gets much closer. I don't mind a little rendering here but it might really disappoint some people

I'm PC based and do quite a lot of chromakey - I get excellent results just by recording the footage in the normal way to the native MP4 format and then use Keylight in After Effects.

Keylight takes a little getting used to as there are a lot of tweaking options but it's well worth the effort to learn it.

I use the Matrox RTX2 card and that keys out green perfectly, shoot in 1920 x 1080 for best results.

I edit on FCP, and use DVmatte Pro from DV Garage.

dvGarage Product - dvmattep3

It combines chromakey with luminance/difference to create a better edge matte. It uses the GPU so it's faster than most too. Not without its curious bugs if you try to use the sublime internal keyer, but if used for two layer stuff (your keyed footage on top of your background), it's great.

Tried shooting 1080p for chromakey, but now stick to 720p for PAL SD, Grass Valley Turbo and HD WMV/YT delivery.

What I am NOT doing, which may make your mileage vary by quite a bit, is motion tracking on chromakey markers for pan/zoom. That's a whole new realm, and at the moment, based on what my clients are asking for, I'm faking it.