Description:24mm lenses are the entry into ultra-wide angle photography. And this lens is the ideal starting point: it's extremely sharp and offers superior correction of linear distortion, and its f/2.8 aperture makes it easy to use with slow, fine-grain films or in low light. It focuses as close as 10 inches (25cm), and for many photograhers gives the ideal combination of a wide-angle "look" without excessive perspective distortion.