The Auto Micro Nikkor is probably the sharpest lens available for 35mm photography. But, even more outstanding is its ability to maintain the same, high standard of image resolution for both general and closeup work - at all camera-to-subject distances from infinity to 1:1, and even closer. The helical system in which the Auto Micro Nikkor is mounted has an extra-long extension range. The lens can be focused from infinity to 9 1/2" (film plane to subject), producing a 1/2-life size image. Use of the M ring, provides a second focusing range from 1/2 life to 1:1. Deeply recessed into the mount, the Auto Micro Nikkor optics are effectively protected against stray light. All glass-air surfaces are hard-coated.