Confusion above--The Canon EF is (confusingly) an FD-mount camera, not an EF mount camera.

If you're invested in FD lenses, the EF is a neat camera. It's built on the old F-1 chassis, is the only camera in the FD line with a Copal Square vertical travel shutter (which gives a 1/125 s. X-sync speed), has MLU, and the meter has a voltage regulator, so it is possible to use it with 1.5 v batteries in general, though when I had one, I found that if the batteries were very fresh, they might be over the rated voltage and wouldn't work properly (in which case I'd leave them in a drawer for a few months to age, use Weincell zinc-air cells in the meanwhile, and they'd be fine).