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) telephoto for Nikon F-mount, using mirrors to fold the optical path and achieve 500mm reach in a compact, affordable package. Mirror lenses provide super-telephoto focal lengths at a fraction of the size, weight, and cost of conventional designs.
The mirror design compresses 500mm into a barrel roughly the size of a standard zoom lens, making super-telephoto reach genuinely portable. The fixed f/8 aperture cannot be adjusted, and the characteristic doughnut-shaped bokeh in out-of-focus highlights is the mirror lens signature — loved by some, disliked by others.
Build quality is budget with functional construction at the lowest possible price point. The lens is manual focus with no electronic communication to the camera body. The compact dimensions and light weight make it easy to carry, though the slow f/8 aperture demands fast shutter speeds.
The Opteka 500mm f/8 is the cheapest way to get 500mm super-telephoto reach on the used market. While image quality cannot match conventional super-telephoto designs, the compact size and negligible cost make it a fun introduction to super-telephoto photography with no financial risk.