Pentax's early medium-format fisheye — the SMC Takumar 6x7 35mm f/4.5 for the 6x7 negative.
The SMC Takumar 6x7 35mm f/4.5 Fisheye is a medium-format ultra-wide lens made by Asahi Pentax for the Pentax 6x7 system. It arrived with the early Takumar 6x7 generation for the camera launched in 1969, giving the large 6x7 negative a full fisheye field of view that no rectilinear wide of the line could match at the time.
This is a manual-focus lens for the Pentax 67 bayonet mount, covering the 6x7 cm frame. It has a maximum aperture of f/4.5 and a fixed 35mm focal length. As a fisheye it renders a curved, wide-angle projection rather than a corrected straight-line image, and the Super-Multi-Coated glass is the coating tier the Takumar 6x7 name denotes.
The fisheye projection bends horizon and vertical lines that sit away from the frame centre, a look photographers use deliberately for interiors, dense landscapes and creative wide shots on the big negative. Depth of field is generous at this focal length, so it is forgiving to focus, and stopping down a little sharpens the corners across the large image circle.
On the used market this early fisheye turns up less often than the standard Takumar 6x7 primes and commands interest from 6x7 shooters. Check the front element for scratches and haze, confirm the aperture blades are dry and snappy, and look inside for fungus given the age. The distinctive rendering also makes it usable on mirrorless bodies through a Pentax 67 adapter.