The Vivitar Series 1 70-210mm f/3.5 (version 1/Kiron) is a telephoto zoom lens offering a relatively strong macro capability to 1:2.2 ratio at 210mm. The 70-210mm offers an outstanding optics in a highly versatile package. The lens has a prong that will meter couple to older Nikon 35mm SLR cameras, hence the Non-AI designation. The lens employs an internal cam mechanism that automatically shifts to 100mm focal length from 70mm when focusing down past 1.6 meters. The lens features 15 elements in 10 groups, 6 iris blades, 34° to 11° angle of view and 67mm filter thread.