Retro reflection

 作者:满曾     |      日期:2019-03-08 08:01:03
By Barry Fox Chromakeying, the TV trick in which actors perform in front of a blue background which is electronically blanked out and replaced by a fake backdrop, has a big disadvantage: studio lighting must be very bright to trigger the blanking electronics. To get round this, the BBC proposes that the actor stands in front of a black material coated with reflective glass beads (GB 2 321 814). The camera lens is surrounded by a ring of coloured LEDs. The light from them hits the beads and bounces back to the camera. The reflected light, which is too weak to colour the actors,