The Canon EF 100-300mm f/5.6 is a telephoto zoom lens with constant max. aperture for 35 mm SLR Canon EF cameras.
As compared to the last FD version, the lens' optical scheme had been completely redesigned, and the lens length had been reduced by 40 mm. The optical scheme comprises 15 multicoated (Super Spectra) elements in 9 groups. The lens is equipped with an Arc Form Drive micro motor and an electromagnetic diaphragm. The lens also features an AF range selector.
It was announced in March 1987 and is an age mate of the EF system. Three months later a more expensive L-version was introduced. With a similar appearance, the lens employed a different optical scheme. In 1990 it was replaced by the 100-300 f/4.5-5.6 USM, featuring an internal focusing system.