Leica Invented Autofocus - Then Abandoned It

In an article over on Apple Mac site Cult of Mac called "Leica invented autofocus, then abandoned it" they take a look at how Leica spent nearly 20 years patenting technology in the late 70s that would take focusing out of the hands of the photographer - but then dropped it, figuring its customers already knew how to focus their cameras. Leica used its Leicaflex SL2 for the autofocus prototype and used a a 50mm lens with a servo motor. Two LEDs on top of the viewfinder assisted in detecting the highest contrast of a subject, while the motor turned the focus ring. Surprisingly, it worked well in low light but wasn’t that fast, because it took a number of gears for the motor to generate enough torque to turn the focus ring. Furthermore, the motor housing was converted to hold six batteries that lasted only an hour! Leica sold the technology to Minolta, which marketed the first successful autofocus SLR with the Minolta Maxxum 7000 just five years later...