Pentax's vintage constant-aperture telephoto — the SMC 70-210mm f/4 for K-mount systems.
The Pentax SMC 70-210mm f/4 is a constant-aperture telephoto zoom from Pentax's manual K-mount era — SMC coating, constant f/4. Pentax K mount.
70-210mm focal length. f/4 constant maximum aperture. SMC coating. Manual focus. Pentax K mount.
The Pentax SMC 70-210mm f/4 is a well-regarded constant f/4 telephoto zoom from the manual focus K-mount era — constant f/4 provides consistent exposure across the telephoto range. SMC multicoating for contrast and flare control. A popular manual zoom for adapted mirrorless use.
On the used market the Pentax SMC 70-210mm f/4 is a constant-aperture telephoto zoom. Condition checks: constant f/4 aperture, zoom mechanism. Pentax K mount.