Sigma's circular fisheye for Nikon DX — the 4.5mm producing full circular images on APS-C.
The Sigma 4.5mm f/2.8 EX DC HSM Circular Fisheye is the Nikon F mount version of the unique circular fisheye described in Canon mount under ID 3557. It produces full circular fisheye images on APS-C sensors — a complete 180-degree hemisphere in a circular image within a black border. One of the very few circular fisheyes for APS-C cameras.
The 180-degree circular image captures an entire hemisphere. The extreme distortion is the creative purpose. Sharpness is good within the circle. The f/2.8 speed enables astrophotography and creative low-light work. HSM motor provides autofocus — unusual for a fisheye. EX professional build quality. The circular image is surrounded by black borders on the sensor.
Nikon F mount, APS-C. Bulbous front element — no standard filters. Weight is approximately 470 grams. Build quality is solid EX professional. HSM motor provides quiet AF. The specialised bayonet lens cap protects the bulbous front element. A niche creative tool for experimental photography and 360-degree panorama stitching.
Uncommon on the used market. Check front element and HSM motor. A specialist creative lens — the circular fisheye effect is dramatic but very specialised. The HSM AF is a practical advantage. Only of interest for creative photography, 360 panorama stitching, and dramatic artistic effects. Not for everyday photography.