How'd they do that?

[nestork]

I was just watching the beginning of a hockey game between the Tampa Bay Lightning and the Montreal Canadians. While the Canadian national anthem was being sung, the entire ice surface looked like a giant Canadian flag. While the US national anthem was being sung, the entire ice surface looked like a giant American flag. Obviously they must have LEDs or a huge LCD under the ice in order to do that.

Does anyone know how it's done?

I expect that at some time they will have to melt the ice. Wouldn't the melt water wreck any electronics under that ice?

[trader_4]

IDK what they did there, but at the Olympics in Sochi they had a similar thing and it was done with projectors.

[gfretwell]

I would guess projectors but it may just be a TV trick that the people there do not see. (like those "first down" lines that pop up in a football game)

[nestork]

Oh, I see. They project an image onto the ice, and the ice reflects that image back just like a silver screen. That makes sense. And, it simultaneously side steps the need to put massively expensive electronics under the ice where they could be damaged if and when the ice melts.

It must be an extremely bright projector bulb to illuminate the entire ice surface like that.

[SteveB]

Just like they put the line of scrimmage and first down lines on football fields, right through the players, but if you are in the stadium, you cannot see them. Was the audience able to see those?

Ateve

[Robert Green]

It's a trick.

I believe it's all done by advanced video overlays. IOW, if you're at the event in person, you don't see it.

It's a reminder that you can't even believe in things that you can see anymore. (-:

[trader_4]

That may be one way of doing something, but without seeing what was actually done at the venue, you have no way of knowing. At the Sochi Olympics it was done with projectors and the people in the stands could see the display choreographed to the performers. It would be really bad if people actually at the venue couldn't see it. And I suspect the same thing was done at the hockey game. It would be pretty lame to have the Canadian flag only visible to viewers, not at the stadium.

[nestork]

No, it can't have been done with projectors because when the Canadian anthem was playing and there was a great big Canadian flag covering the entire ice surface, I didn't see the Tampa Bay Lightning logo that's clearly visible in the middle of the arena ice when the flags weren't there.

So, I can see how a projector could produce a Canadian or American flag onto the entire ice surface, but how does ADDING light remove the logo and the 4 face off red dots and circles?

The only thing that makes sense to me is that the flag was put into the TV signal so that the people in the arena couldn't see it, and the people at home could see nothing but the flag.

If those flags were done by projecting light onto the ice, the Tampa Bay Lightning logo would still be visible to everyone in the arena and everyone watching at home. And, in the case of the Canadian flag, that would muck up the appearance of the Canadian flag by messing up it's central red maple leaf. And I recall clearly that it was a normal Canadian flag, with no hockey team logo messing up the red maple leaf, and no face off dots and circles messing up the red bands on either side of the maple leaf.