Sigma 20mm f/1.4
Sigma 20mm f/1.4 DG HSM Lens is a member of the venerable Art series of Global Vision lenses from Sigma. And pairs a sophisticated optical design with robust physical construction. Comprised of 15 elements in 11 groups, the lens design includes two “F” Low Dispersion (FLD) elements. Five Special Low Dispersion (SLD) elements, and two aspherical elements to significantly reduce chromatic and spherical aberrations. As well as limit distortion for clean, sharp and evenly illuminated imagery. A Super Multi-Layer Coating has also been applied to minimize surface reflections, flare, and ghosting for increased contrast and colour accuracy. The wide focal length and consistent image quality make this lens especially suitable for landscape, interior, architectural, and astrophotography applications, while the fast f/1.4 maximum aperture deems it ideal for natural and low-light shooting.
Complementing the optical performance is an equally adept Hyper Sonic Motor, which provides fast, smooth, and near-silent autofocus performance. This focusing motor also enables full-time manual focus override. At any time just by rotating the focus ring for refined manual control and focusing as close as 10.9″.This optical design also helps to control distortion and limit vignetting.
The HSM also permits full-time manual focus control simply by rotating the focus ring at any time.
A rounded nine-blade diaphragm helps to produce an attractive out-of-focus quality.
A fixed petal-shaped lens hood helps to reduce lens flare. When working in strong lighting conditions and also offers some protection to the front element of the lens.