[DTV]

That's the point I've been making. I don't think there is enough 'green' to produce anything to key out. CSO surroundings need to be quite brightly lit, hence why these studios are startlingly bright. That's why they have a CGI overlay of the desk as a different layer of the VR environment.

I don't think they can key out areas which are 'almost green'. You'd have elements of your set disappearing all over the place.

Depends on how advanced the chromakey system is - ITV's is clearly quite good at removing almost green bits.

The key bit in the video is from about 03:06 to 03:14 - you can clearly see the view of the rostrum through the desk disappear as the reflection on the desk gets greener. It's definitely chromakeyed rather than overlayed, not least as you wouldn't be able to see through the desk at all if the image was overlayed on top of the main CSO footage. Plus, I don't see how any overlay would be able to achieve the reflections of presenters, keyboards, etc. - that could only be gained through the standard chromakey technique.