The Nikon 600mm f/4 ED IF AI-S, last manufactured in 1986, is a super telephoto manual focus prime lens. This 600mm vintage prime lens was typically employed by photojournalist when getting close to a subject was impractical.
The internal focusing (IF), auto indexing second generation (AI-S), lens employs extra-low dispersion (ED) glass elements to ensure superior image quality and compensates for aberrations. The lens construction consist of eight elements in six groups with two ED glass elements. The lens has a relatively impressive 12x magnification and a bright f/4 max aperture to achieve higher shutter speeds.