The image distortion occurs more or less with a wideangle lens on, but this particular lens is especially made for Distortion Free（-1.3％） based on the sophisticated lens formula which produces a resolution power of 350-line/mm at center（MTF30%）. Especially designed for use with high-definition digital camera, and the lens is made of hi-index optical glasses, 3-group/3-element, fully coated. It's an ideal accessory lens for professionals and advanced amateurs shooting in tight place. There will be no reduction of light value when this conversion lens is attached on the camera's lens.