Extraordinarily sharp, last evolutionary step for Nikon design of 24mm f2.8 manual focus lens. Floating element design results in remarkable resolving power at all reproduction ratios. 84 degree angle of coverage when focused at infinity. Compact design for what is achieved. One of the very sharpest lenses for its angle of coverage ever executed.
As illustrated in the sketch, CRC is achieved by movement of the rearmost (rightmost) 3 element 2 group lens cluster.
Introduced just eight years after its embarrassing first wide angle offerings with the original Nikon F, this lens was a triumph. Using a floating element "CRC" (Close Range Correction) this lens formulation is extraordinarily sharp through out its entire focusing range especially at 2 stops down and maintains a relatively flat field at all ratios, though not recommended for reproduction work. The earliest version does have multiple coatings on some internal elements, full fledged "NIC" had to wait for the second version of this lens.
Version one:
Introduced June 1967 SNs 242803 thru 353252: NKJ designation, Nikkor-N inside the filter ring, Blue lens coating, Depth of field scale on the textured chrome grip ring body.
Version two:
Introduced during 1972 SNs 370001 thru 434287 NKJ eliminate in favor of "Nikon" and Nikkor-N pick up a DOT "C" designating "
NIC" for Nikon's Multicoating trademarked improved reduced reflectance lens coatings.
Version three:
May 1977 onset SN 450001, physical design facelift: F-Stop range increased to F22 with no change in optical formula, scalloped focus ring eliminated in favor of RIRF (hard Rubber Insert Focus Ring) and textured chrome lens body eliminated in favor of a satin black finish.
Version four: Onset SN 525001 introduced during 1977. AI mechanical embodiment. Similar in appearance to version three but physically more compact reflecting a brand new optical design with again nine elements but this time arranged in nine groups.
Version five (December 1981):
AIS version; essentially similar to version four but with addition of precise aperture control through rear coupling link.
Version six (1988): First AF version with narrow manual focus ring.
Version seven (November 1993) : AF-D version with wider rubberized focus ring.
