Canon — f/4.5 autofocus telephoto zoom, 100-200mm lens for early EOS film cameras, EF mount
Canon EF 100-200mm f/4.5A was an affordable telephoto zoom for Canon's EOS autofocus system, released in December 1988 as the EF lineup's mid-price answer to photographers wanting extra reach without paying for Canon's L-series telephotos.
It used 10 elements in 7 groups behind an 8-blade diaphragm closing to f/32, with a 58mm filter thread, a 1.9 metre minimum focus distance, roughly 0.13x maximum magnification, and a weight of 520 grams.
The 'A' suffix marked Canon's Arc-Form Drive motor, quieter than a basic micromotor but slower than ring-type USM. A one-touch push-pull zoom action and constant f/4.5 aperture kept handling simple, though contrast and edge sharpness trailed Canon's L-series telephotos of the era.
It appears occasionally in UK used listings at modest prices reflecting its consumer-grade AFD-era status. Buyers should test the autofocus motor for smooth operation, check the push-pull zoom collar for looseness, and inspect the front element for coating haze.