Pentax's telephoto for 645 system — 200mm f/4 for medium format portrait and nature work.
The Pentax-A 645 200mm f/4 is a telephoto prime for the Pentax 645 medium format system (6×4.5cm). The 'A' designation indicates automatic aperture coupling (compatible with Pentax 645 program modes). 200mm on 645 provides approximately 125mm equivalent. Pentax 645 mount.
f/4 maximum aperture. 200mm focal length (Pentax 645 medium format). 'A' designation (automatic aperture coupling). Manual focus. Pentax 645 mount.
The Pentax-A designation enables automatic exposure modes on the Pentax 645 body. 200mm on 645 provides portrait-to-moderate-telephoto reach — approximately 125mm equivalent on full-frame. A practical telephoto for portrait and wildlife on the 645 system.
On the used market the Pentax-A 645 200mm f/4 is a medium format telephoto. Condition checks: front element for marks, aperture blade condition, automatic aperture coupling. Pentax 645 mount — 645 system only.