Pentax SMC Pentax 67 800mm f/6.7 ED [IF]

Smaller, slower, and substantially less expensive alternative to the 800mm f/4 ED — same focal length, same ED glass and internal focusing, but f/6.7 maximum aperture instead of f/4. Released in the late 1990s alongside the Pentax 67II to broaden access to 800mm focal length for the system.

The 1.5-stop slower aperture compared to the f/4 cuts weight, size, and price by significantly more than half — a much more practical lens for photographers who need 800mm reach but cannot justify the extreme weight, size, and cost of the f/4 super-tele. Image quality is excellent throughout the aperture range; the f/4 advantage matters mostly for low-light subject isolation rather than overall sharpness or color rendering.

Mounts on the outer bayonet. Tripod use is mandatory but the lighter weight makes setup and transport meaningfully more manageable than the f/4. Used primarily for wildlife and distant landscape on tripod; the f/6.7 maximum aperture is dim enough that handheld use is impractical at typical shutter speeds.