14mm F2.8 AF Full Frame Weather Sealed Wide Angle (Nikon F) F2.4 2 means that the lens

2 means that the lens is effective in low-light shooting and can produce a shallow depth of field when the lens is closer to the subject

polarizers

4 also performs with Canon APS-C sensor cameras as a high speed 136mm equivalent AF telephoto lens

and is the lightest and smallest AF full frame 35mm F1

14mm F2.8 AF Full Frame Weather Sealed Wide Angle (Nikon F) F2.4 2 means that the lensThe 14mm F2. 8 AF lens is designed for high resolution, well corrected imagery with the most advanced Nikon Full Frame image sensor cameras. It can also be used on APS C Nikon models where it will provide a 21mm equivalent focal length. State of the art manufacturing techniques and an advanced optical design (15 Ultra Multi Coated elements in 10 groups including 2 Aspherical, 1 Extra Low Dispersion, and 4 High Refractive Index) minimize aberrations,