The oldest lens I own is the EF 70-210mm F/4 lens from 1987. Its still working today and fungus free. But it is slow to focus. But when the lens originally came out people weren't worried about the speed. Instead they wanted the camera and lens to focus automatically. When adapted it acquires focus much faster when adapted despite not supporting all of the features. It also gets some IBIS when on a body equipped with it. The lens aperture motor is quite slow. But this is a restriction of Arc Form Drive (AFD) lenses. They cannot carryout AF & aperture control at the same time when the camera is set to Servo AF as newer lenses can. Micro Motor ended up solving all of the problems AFD suffered from. USM lenses never had such restrictions and they date back to 1987. But these lenses weren't the same as newer EF USM with a clutch override for focus. Instead these lenses were Focus-By-Wire like STM and Nano USM lenses. Fun Fact the EF 300mm F/2.8L USM lens was the first Ring Type USM lens released by Canon in November or 1987. This lens was also Focus-By-Wire its a little weird to use focus override because it doesn't work with the camera set to Servo AF. Also lenses released between 1987- August 1991 used Arc Form Drive as the AF motor. Many of these lenses were replaced early on with Ring Type USM or Micro Motor versions. Note some AFD lenses such as the EF 50mm F/2.5 Compact Macro lens would remain in production as late 2022. All AFD lenses were made in 1 factory in Japan and nowhere else. Canon even made 4 L lenses with this AF motor type. Though replacement lenses would feature USM motors instead of AFD due to speed limitations.
EF 300mm F/2.8L USM lens
