The Canon EF (Electro-Focus) lens mount system was introduced by Canon in 1987. It is designed for use with Canon's digital and film cameras, allowing for automatic focusing and exposure control. The EF mount supports a wide range of lenses, including prime and zoom options, catering to various photography needs. Canon EF lenses are known for their high-quality optics and durability. They are compatible with both full-frame and crop-sensor cameras, making them versatile for different shooting styles. The system has evolved over the years, incorporating advanced technologies like image stabilization and ultra-sonic motors for faster focusing.