The NHK Twinscam is a digital-optical-mechanical video camera system designed by the Japanese broadcaster NHK for covering aquatic sports events.
It uses digital image processing technology to combine video from two synchronized motion-controlled cameras, one above water and one underwater, in real time, to create the illusion of a view from a single camera that can look through air and water at once as if they had the same refractive index.
[1] It was used at the 2012 London Olympics to televise the synchronized swimming events.
It has been used for the same purpose in Japan since 2010.
[2] This Asian television-related article is a stub.