Advanced optical design has been used to overcome the distortion prone tendency of ultra wide angle lenses to control distortion without digital correction this contributes to achieving high resolution to all corners of this ultra wide angle lens the lens structure consists of 10 elements in 7 groups including 2 aspheric and 3 extra low dispersion elements and a seven blade rounded diaphragm the lens features distance and depth of field scales on the barrel making it suitable for a range