Manual focus prime lens for Pentax K-mount cameras.
The Pentax 100mm f/4 is a short telephoto lens for the Pentax K mount, covering portrait and documentary telephoto work. Without a Macro or Soft designation, this is likely the SMC Pentax-M 100mm f/4 standard telephoto from the compact M-series range.
100mm focal length, f/4 maximum aperture, Pentax K bayonet mount, likely SMC Pentax-M series compact design.
The 100mm f/4 provides a moderate telephoto perspective useful for portraits, details, and light documentary photography. The f/4 maximum aperture is modest but delivers good image quality. Compatible with all Pentax K-mount cameras.
Inspect for fungus, haze, and coating condition. Confirm K-mount engagement. Check aperture blades. Test focus helicoid smoothness.