Pentax SMC Pentax 67 Fish-Eye 35mm f/4.5

The Pentax 67 system's only fisheye lens — a diagonal fisheye covering approximately 180° corner-to-corner on the 6×7 image area. Originally released with the Pentax 6×7 body in 1969 as the Super-Takumar 35mm f/4.5 Fish-Eye, later updated through SMC Takumar and SMC Pentax 67 generations with improved coatings.

The 6×7 fisheye produces a distinctive curved-horizon look not replicable on smaller-format fisheyes — the larger negative size means the image-circle distortion plays out across more film area, producing more dramatic foreground / sky curvature in landscape compositions. Used for landscape (especially storm-cloud and wide-vista work), surveillance and security documentation, and abstract / surrealist photography where the dramatic distortion is the point.

Mounts on the inner bayonet ring (Pentax 67 lenses ≤300mm focal length use inner; ≥400mm use outer). Filter use is unusual on a fisheye — there's no standard front filter thread; rear gel-filter slots typically handle filtration when needed.