Sigma's full-frame diagonal fisheye — the 15mm f/2.8 for creative wide-angle effects on Nikon.
The Sigma 15mm f/2.8 EX DG Diagonal Fisheye is a full-frame diagonal fisheye for Nikon F mount. At 15mm on full frame, it produces a 180-degree corner-to-corner fisheye image filling the entire rectangular frame. The EX designation indicates professional build quality. The D designation indicates Nikon AF coupling compatibility.
As a diagonal fisheye, extreme barrel distortion is the creative intent — straight lines curve dramatically except through the exact centre. Sharpness is good across the frame. The f/2.8 aperture is fast for a fisheye, useful for astrophotography and low-light creative work. DG coatings reduce sensor reflections. The fisheye effect is dramatic and eye-catching.
Nikon F mount with D-type coupling. Filter thread uses a rear gel filter holder — the small front element accepts rear-mounted gelatin filters. Weight is approximately 370 grams — compact. Build quality is solid EX professional grade. Screw-drive AF. The front element is relatively small and slightly recessed, offering some protection.
Available on the used market at moderate prices. Check front element and AF operation. A capable full-frame diagonal fisheye for creative and astrophotography work. The fast f/2.8 enables Milky Way fisheye shots. Also useful for 360-degree panorama stitching where software corrects the distortion. The Samyang 12mm f/2.8 Fisheye is the main competitor.