Compact and lightweight lens with orthodox 6 elements in 5 groups. High image quality with a good balance of aberration correction is obtained throughout the entire focusing range from the closest focusing distance of 0.45m to infinity. Micro-motor operated AF system. This lens was improved to become the model II by simplifying the focusing distance window and manual focus ring. How does the EF 50/1.8 perform in practice? Well, like all fast lenses it's a little softer wide open than stopped down. However even wide open it's still not bad and in fact a little softness can sometimes be useful when the lens is used for portraits! On any 1.6x sensor body (such as the Digital Rebel (XT), EOS D30, D60, 10D and 20D) a 50mm lens has the same field of view as an 80mm lens would on a full frame camera, so an EF 50/1.8 is a very good portrait lens for use with such APS-C sized sensor DSLRs.READ MORE