Canon's FD full-frame fisheye — the 15mm f/2.8 S.S.C. with a 180-degree diagonal field.
The Canon Fish-Eye FD 15mm f/2.8 S.S.C. was introduced in 1973 as a full-frame diagonal fisheye for the Canon FD manual-focus system, part of the first FD generation carrying Super Spectra Coating. Unlike the circular 7.5mm, it fills the entire 35mm frame with a 180-degree diagonal field, making it the practical fisheye choice for most users of the era.
This is a manual-focus Canon FD lens with a fixed 15mm focal length and a maximum aperture of f/2.8. It is a diagonal fisheye that covers the full frame corner to corner, and it uses built-in filters selected by turret rather than a front screw-in filter. Focus and aperture are set manually on the FD barrel.
A full-frame fisheye of this type curves straight lines toward the frame edges while keeping the centre relatively natural, producing the familiar dramatic wide look without the round image of a circular fisheye. It suits landscapes, tight interiors, action and creative work where the strong perspective is used intentionally, and depth of field is very deep at all settings.
On the used market the FD 15mm fisheye is sought after by adapter users, so check the bulging front element carefully for scratches and cleaning marks. Inspect for haze, fungus and oily aperture blades typical of the age, confirm the built-in filter turret operates, and test the aperture ring for smooth clicks. It adapts well to mirrorless via an optics-free FD adapter.