Canon's first EOS camera had the latest technologies including a super microcomputer and a Canon-developed BASIS sensor for high-precision AF. The EOS 650 boasted incomparable autofocusing. Each EF lens has its own optimum built-in motor for autofocusing, and only electronic signals are exchanged between the lens and camera body. It is an ideal AF system. Since there is no high-torque driving noise, autofocusing is quick. The high-precision Ultrasonic Motor (USM) was also developed successfully. EOS was the start of a new and unique series of AF SLR cameras.

EOS 650 QD (released in September 1987) is an EOS 650 with a quartz date back.