Budget Opteka mirror lens at 500mm f/8 for Nikon, cheapest possible super-telephoto reach in compact form.
The Opteka 500mm f/8 Reflex is a budget mirror (catadioptric) super-telephoto for the Nikon F mount from Opteka, a budget lens brand. f/8 is fixed (no aperture adjustment). Mirror design uses a folded optical path for a compact barrel. Nikon F mount.
f/8 fixed aperture. 500mm focal length (full-frame super-telephoto). Mirror/catadioptric design. Manual focus. Compact barrel for focal length. Nikon F mount.
The Opteka 500mm f/8 Reflex provides budget super-telephoto reach at the cost of a fixed f/8 aperture — exposure is controlled via shutter speed only (or ND filters). The characteristic doughnut-shaped bokeh from the central mirror obstruction is a known trade-off. Manual focus.
On the used market the Opteka 500mm f/8 Reflex is a budget super-telephoto option. Condition checks: mirror surfaces (internal), focus ring. Nikon F mount — fixed f/8 mirror lens.