It's not computer graphics - the coin really does float and spin.
Magician Walt Noon performs a floating coin illusion. Do you believe him when he says he isn't using any camera tricks? When we watch this on video, it does look like it's camera trickery such as computer graphics, so it doesn't impress us as much as it should. Some magic tricks look too fake when they're seen on video, so they must be seen live to prove they are magical.
I could tell you that this is not trick photography (and I can tell you, it isn't) but then you'd have to trust me, wouldn't you?
Walt Noon's Levitating Coin Trick