Sigma Fixed Focal Length Lens With innovative, state-of-the art technology, Sigma s complete line of lenses expand your ranges of photographic possibilities. Sigma lenses are designed to be sharp, versatile, ergonomic and unmatched for low weight and compactness. Sigma s fixed focal length lenses range from full macro capabilities to wide and ultra-wide lenses. Some are equipped with a HyperSonic Motor (HSM) for added power and convenience, while still others are ultra-compact to make them lighter and easier to use, especially when shooting on the road. There s simply nothing like a 180 degree fisheye to turn ordinary scenes into extraordinary photographs. With this one, no special finder is required and an integral lens hood helps minimize glare. Thanks to its unique 8-element/7-group design and multi-coating, contrast and edge definition are excellent. A rear filter holder accepts gelatin filters. Weighs only 10 oz. Includes 4 Year Service Plan (1 year international warranty plus 3 years extended warranty). Item Specifications: Product Description: Sigma EX fisheye lens - 15 mm Weight: 13 oz Length: 3 in Min Focus Range: 5.9 in Lens System: Fisheye lens Lens Aperture: F/2.8 Focus Adjustment: Automatic, manual Focal Length: 15 mm Mounting Type: Nikon F Lens Construction: 6 group(s) / 7 element(s) Special Functions: Fisheye