A budget mirror/reflex 500mm telephoto in Canon FD mount — extreme reach at minimal cost.
The Tokina 500mm f/8 is a mirror (reflex/catadioptric) telephoto lens in Canon FD mount. Mirror lenses use a combination of mirrors and glass elements to achieve extreme focal lengths in a compact barrel. The fixed f/8 aperture is inherent to the design — there is no variable aperture. It provides 500mm reach for wildlife and astronomy at minimal cost and size.
Optical performance has the distinctive characteristics of mirror lenses. Sharpness is acceptable in the centre but falls off towards the edges. The signature feature is the doughnut-shaped bokeh in out-of-focus highlights, caused by the central obstruction mirror. Contrast is lower than refractive designs. The fixed f/8 aperture demands bright conditions or high ISO settings.
Canon FD mount — requires an adapter for modern camera systems. No filter thread at the front; rear drop-in filters may be possible depending on the version. Weight is approximately 450 grams — remarkably compact and light for 500mm. Build quality is solid metal. Fully manual focus with no aperture control. The compact size is the mirror design's key advantage.
Very cheap on the used market — often under £50. Check for clean mirrors and smooth focus. The doughnut bokeh and low contrast limit its appeal for conventional photography. Best treated as a novelty or ultra-budget entry to super-telephoto reach. Any modern 150-600mm zoom is dramatically better in every measurable way.