Technology

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  ED (Extra-Low Dispersion) Glass

  An optical glass developed by Nikon that is used with normal optical glass in telephoto lenses to obtain optimum correction of chromatic aberrations.

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  AS

  AS stands for Aspherical lens elements. This type of lens utilizes non-spherical surfaces on either one or both sides of the glass in order to eliminate certain types of lens aberration.

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  A-M

  A-M stands for Auto-Manual Mode. Thanks to a mechanism incorporated in the lens barrel, smooth focusing operation in Manual focus mode is realized in the same way as users have become accustomed to with conventional manual-focus lenses by adding an appropriate torque to the focus ring.

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  Rear Focusing System

  A system in which only the rear lens group moves during focusing, thus eliminating changes in the physical length of the lens during focusing and enabling faster focusing. Such lenses are designated with RF on the lens barrel.