Legendary In The World Of Close-up Photography, Superior Micro Nikkor Performance Delivers Images Of Striking Clarity While Providing Reproduction Ratios Of Up To 1:1 Without Additional Accessories. The Extra Long Focal Length Of This Lens Provides The Most VerSatile Working Distance. Extra Low Dispersion (ed) Glass Ensures Apochromatic-like Performance, With High Contrast And Sharper Images. Ed Glass Has Been Incorporated Into Selected Elements For Superior Optical Performance. Internal Focusing Improves Handling And Focusing Operation. Focuses From Infinity To 19.4 (1:1 Reproduction Ratio). A-m (automatic-manual) Switch.