ATV television prismatic optical effects unit, c 1972

Television prismatic optical effects unit, formerly used by ATV, 1967-1977. A large metal and plywood frame with a set of different types of circular multiple image mult-sector prisms which mount into it - used for creating multi-image and 'kaleidoscopic' effects by placing the unit in front of the television camera lens. A moving 'kaleidoscopic' effect can be created by a studio technician turning a crank handle (connected to a leather belt) at the desired speed which rotates the prism. 'Six' interchangeable prisms, which were acquired with the unit, can create different numbers of simultaenous and/or concentric images of the same scene. These effects were frequently used in music videos of the 1960s-1980s, and also on 'live' pop music programmes such as 'Top of the Pops'. This particular unit is believed to have been the one used in the production of Queen's famous 'Bohemian Rhapsody' video during the chorus sequences where multiple images of the group appear simultaneously.