Sigma’s 4.5mm F2.8 EX DC circular fisheye HSM creates an image that is circular, curved, distorted view of reality when used on digital SLR camera. One of most unusual lenses photographer can use as it produces circular image within black surrounding frame. It is ideal for landscapes and panoramic photography. Because of its equisolid angle projection system, lens can be used for scientific applications. Minimum focusing distance of 5.3-inch allows photographer to have fun with placement of subjects extremely near to camera with distorted backgrounds. SLD (special low dispersion) glass employed for effective compensation of color aberration, super multi-layer lens coating reduces flare and ghosting and assures high image quality throughout entire focal range. In hands of photographer looking for creative expression and opportunity to explore and create, this is ultimate creative tool. The results are captivating.