Designed to match the APS-C size image sensors of Nikon digital SLR cameras, the Sigma 30mm f/1.4 lens is an ideal choice for a wide range of applications, including snapshots, portraiture, indoor shooting, and landscape photography. The 30mm lens relies on two special-low-dispersion glass elements and a glass-mold aspherical lens. Combined, the construction details correct for all types of chromatic and color aberrations. Other features include a maximum aperture of f/1.4, a 62mm filter mount, and a one-year warranty.
Specifications

Focal length: 30mm
Maximum aperture: f/1.4
Lens construction: 7 elements in 7 groups
Angle of view: 45 degrees (SD format)
Number of diaphragm blades: 8
Minimum aperture: f/16
Minimum focusing distance: 15.7 inches
Maximum magnification: 1:10.4
Filter size: 62mm
Corresponding AF mounts: Nikon
Dimensions: 2.97 inches in diameter and 2.3 inches long
Weight: 15.2 ounces
Warranty: 1 year

Large maximum aperture of f1.4
The most appropriate coating for digital SLR cameras
Two SLD (Special Low Dispersion) glass elements and an hybrid aspherical lens, provides the utmost correction for all types of aberrations

This large aperture 30 millimeters f1.4 EX DC lens is designed to match the APS-C size image sensors of digital SLR cameras. Two SLD glass elements are especially effective in the compensation of magnification chromatic aberration. Glass mold aspherical lens at rear group of lens reduces color aberration and provides high-quality image results.
From 40 centimeter (15.7 inches) minimum focusing distance to infinity, this lens creates very sharp images with high contrast.
Large maximum aperture of f1.4 can perform superbly in a great range of applications, including snapshots, portraiture, indoor shooting and landscape photography.
Note to customers: Vignetting will occur if the lens is used with digital cameras with image sensors larger than APS-C size or 35mm SLR cameras.