Photography has been evolving well over the years since the first camera was invented in the early 19th century in the form of a pinhole box. Autofocus however, did not exist until 1978. It took another few years for AF to find its way into a 35mm SLR in 1985. Not to be left behind in the new technology race, Canon, in the same year, decided to develop "a highly refined AF SLR system".
After two years of research and development, a brand new EOS (Electro-Optic-System) took the world by storm with the launch of the EOS 650 camera. One of the revolutionary innovations was planting the AF drive motor in the lens itself instead of camera body, an industrial standard then. Coupled with the world's first use of USM in the lens, it redefined fast and precise AF in SLR lens forever. Since then, the Canon EF lens has grown to become the largest and most extensive range of SLR lens in the world. Along the way, some of the most extraordinary lenses were born. For example, the EF50mm f/1.0L USM and EF1200mm f/5.6L USM.