Product Features Mount with dust- and splash-proof structure The mount features a special sealing to make the lens an excellent choice in a wide variety of conditions.   Rounded diaphragm The 9-blade rounded diaphragm creates an attractive blur in the out-of-focus areas of the image.   Designed to minimize flare and ghosting From an early stage in the lens design process, flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. SIGMA’s Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions.   High-precision, rugged brass bayonet mount The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens.   Compatible with Lens Aberration Correction Matching the optical characteristics of the lens, this function performs in-camera corrections of peripheral illumination, chromatic aberrations, distortion, and more, to further enhance image quality   1 YEAR WARRANTY