Telephoto zoom lens for PKA mount cameras.
The Sirius 70-210mm is a consumer telephoto zoom manufactured under the Sirius brand for Pentax K-mount cameras. The PKA mount designation indicates Pentax K with A-type aperture coupling, enabling program auto-exposure on A-mode compatible Pentax bodies. Sirius lenses were budget third-party options for the consumer SLR market.
70–210mm zoom range, f/4-5.6 variable maximum aperture (presumed), PKA (Pentax K with A-type aperture coupling), manual focus or early AF.
A budget telephoto zoom for Pentax K-mount cameras with A-type aperture coupling. The 70-210mm range covers portrait to moderate telephoto for general use. Performance at f/8 is adequate for casual photography. PKA coupling enables program modes on compatible Pentax bodies.
Inspect for fungus, haze, and coating condition. Test A-mode aperture coupling on a compatible Pentax body. Confirm K-mount engagement. Check zoom mechanism.