Overview

The Sigma 4.5mm F2.8 EX DC HSM Circular Fisheye is a unique lens for APS-C sensors, offering a full 180° circular field of view. Optically, it is sharp in the center but suffers from high chromatic aberration at the edges. Build quality is solid with a metal mount, though autofocus is fast and manual focus rarely needed. It suits creative photographers wanting extreme perspectives, but requires careful framing to avoid including the photographer.