Canon EF-M22mm F2 STM Single-Focus Wide-Angle Lens, Mirrorless Camera Compatible, Black

Aspherical lenses were developed to solve three problems: spherical aberration correction for large-diameter lenses, distortion aberration correction for wide-angle lenses, and miniaturization of zoom lenses. STM is an abbreviation for stepping motor. It is used to drive focus lenses. After one-shot AF, this function allows the photographer to instantly switch to manual focus by simply rotating the focus ring so that the photographer can make the final focus adjustment after autofocus. 5985B005AA