There's so much tweakability in good keying software I'd wonder why you'd bother with a RT keyer unless you had a rather expensive unit. If you need a RT keyer though Datavideo make a fairly cheap unit (DVK100). Results I saw were passable. I guess if you can get it looking good out of that unit then you know you're on the right track and things will only get better with good keying software.

Bob.

I wish we had dvMatte Pro 3 adapted for Vegas.

GPU-accelerated Real Time Keying, Color Matching, Light Wrap (which can make a huge difference when selling a greenscreen composite), automatic Spill Suppression, Edge Blending, 2 color differences keyers and a hybrid luminance keyer working in unison, all for $199.

How do you adapt a real-time add on to a program that doesn't do real-time input/output at all? Vegas doesn't have any ability to show you on the screen what's coming down the wire, with or even without effects/keying/compositing/overlay, etc.

Vegas with real-time keying just wouldn't be Vegas anymore. It would be something else completely. Maybe VidCap on super-steroids?

I think there may be some confusion due to the terminology being used. In the realm of NLEs, "real-time" has referred to something that can be played back and full speed without needing to first render (sometimes by lowering the quality/resolution of the image). For instance, Vegas has many real time filters as we can apply them to a clip and see the result at full speed without needing to render the clip.

In this respect, Vegas already does have a real time chroma keyer, as we can see the results of a key without having to render the clip it was applied to.

On the other hand, I think what the original poster was referring to is "live" chroma keying. This would enable a user to use live video as a source and apply a key to check the quality of the setup in the studio (lighting, etc.). To my knowledge, no NLE has this functionality (would be very interested to know of any real NLE that has this as a feature).

There are other tools that do provide what you are looking for, however:

Windows:
Adobe Ultra CS3
http://www.adobe.com/products/creativesuite/production/ultra/
(Included in Production Premium or Master Collection bundles - starting at $1699)

Not the best keyer out there, but pretty useful for monitoring a live feed and seeing how well it will pull a rough key. This is important because small adjustments on set to optimize a shot can make a huge difference in post when compositing your greenscreen footage.

Mac:
Conduit $199
http://www.dvgarage.com/prod/prod.php?prod=conduit2

A very good nodal compositor. This program was originally made available as a plugin for FCP and Motion, but the latest version now comes with plugins for After Effects AND Photoshop (Windows and Mac) as well. However, the cherry on top is that it also comes with a standalone version that lets you choose a live video feed as a video source. This means that you can work with live footage on set and build a node setup to pull a perfect key for use during post production. Another nice thing is that you also get a full set of live scopes so you can further inspect the video to optimize the shooting environment to get an even better key (this is similar to what you could do with Adobe OnLocation CS3 that comes with the Adobe bundles listed above). This is a very powerful tool with a lot of control. I just wish the Windows version had live capability like the Mac version :(

Both of these apps use the GPU to get real-time playback (most of the time), so feedback is pretty much instant.

"To my knowledge, no NLE has this functionality"

Yes, this is NOT a typicall NLE, but a live switcher feature.

Marco

Although not a "live" keyer, this program works surprisingly well (and it's free.)

CineGobs Keyer