This capability has been around for at least 15 years. The Ultimatte, which was a hardware based chroma keyer, would allow you to have smoke over a green screen, such as a candle or cigarette and still gave a very clean key.

Dave T2

Am I right in thinking that the shadow isn't changing as he gets closer and farther from the screen? It looks weird. He's got light all over him but I only see one shadow.

If they're adding a shadow, that's mostly math and transfer modes. Not terribly hard as long as the hardware can keep up.

Rob

Off Topic .... but releated to this thread....

I've noticed that at least one local station seems to be using a (very) large flat screen display for the weatherman instead of a green screen. Not sure how big .. but I understand 80 to 100 inch models are now available.

That would explain the shadow which does precisely follow the weatherman.
JJK

Not sure how they do it now, but Serious Magic's Ultra 2 had shadow capability.

Adobe Ultra was included as part of CS3 Master Collection, at least; I know because I've got it in among my install discs (it came on a separate disc; as did OnLocation). I'm not sure what its status was with CS4, but in CS5 and CS6 I believe it was simply reduced to a Premiere Pro plug-in also called "Ultra". I'm not sure about the plug-in's capabilities and how they compare to the standalone software, though, as I haven't yet upgraded to CS6 (but plan to).

The CDL CD480 vision switcher, released in around 1978 had this facility on its RGB chromakeyer.

Serious Magic's Ultra has been absorbed into Adobe's CS line. "Ultra Key" is what it is called and it's in the Effects > Keying palette.

Ultimatte, for whatever reason, was rendered obsolete. It always gave me the best keys IMHO.

When/if I want a Shadow to follow my keyed object, I'll either render out a file w/Alpha then add a Drop Shadow when brought back in to the NLE or add a Drop Shadow in the FX Chain after the Key.

If done right, it can add a touch of realism to the environment. If done wrong, it's immediately noticeable. (use with caution)

I just received an "E" mail from WEWS Cleveland and they state that they use a greenscreen and that there is no shadow. I am in total disagreement. They are the only channel that has a shadow on the weather with my OTA Sony XBR2. The shadow is extremely obvious. Then again, maybe I have to go to shadow school.
Another weather person said they do not see a shadow on the green screen wall.
JJK

Ultimatte, for whatever reason, was rendered obsolete.

I'm sure that the people currently selling the latest version of this hardware would be a little surprised to hear that!!!

Don't forget colour sub-sampling (compression). Most broadcasters will use cameras with lower colour sub-sampling compression (4:2:2).

The short (and I'm sure very bad explanation) is this: the human eye is better at detecting brightness over colour detail. So in video, we preserve brightness (chrominance) and compress the colour (chrominance).

To horribly over-simplify: the average handicam will compress the beans out of the colour (4:2:0). That means there's in the range of less than half the colour information of 4:2:2. Compressing 4:2:0 video makes for ragged edges and little hope for preservation of near transparent objects, hair detail, etc.

The upshot is that the broadcast camera and accurately see and reproduce those colours more effectively and keying is fantastic (and a pleasure in software). Ever wonder how smoke and transparency is keyed in movies? There are digital cinema cameras that, effectively, don't compress colour at all (4:4:4). There's so much colour detail that transparencies can be preserved.

This is sort of off topic, but this link shows you (in After Effecs) how transparencies can be preserved. If you don't use AE, it's going to be a lot of gobbledeegook, but it's a fair illustration/tutorial of preserving transparencies can be done. http://www.videocopilot.net/tutorial/advanced_soft_keying/

All that said, there's also the aforementioned hardware that does the same thing. It's a subtle effect, and frankly, I don't care either way since I don't find people without shadows unnerving (unless they're vampires).

"I'm sure that the people currently selling the latest version of this hardware would be a little surprised to hear that!!!"

It's also now available as a plugin.

Depending on options under $1,900. It doesn't look like Vegas is on their list of supported hosts.

Bob.