Sigma 20mm f/2 DG DN Contemporary Fullframe Sony E-Mount lens ($699) is a compact prime with f/2 aperture ideal for landscape, cityscape and astrophotography. Wide, bright, and light, it is equally useful as a video lens, and particularly well suited for handheld vlogging and livestreaming.
Optical Design consists of 13 elements in 11 groups, including one F Low Dispersion (FLD), one Special Low Dispersion (SLD), and three aspherical elements. Distortion is minimal, imaging is sharp, and bokeh is smooth. On an APS-C format camera, 20mm turns into a 30mm-equivalent focal length. You can get as close as 8.7 inches from your subject for creative close-ups, a 1:6.7 magnification ratio.
The seventh of Sigma’s I-series of lenses, the new prime shares a number of stylish and functional design features with previous models, including all-metal construction, a manual aperture ring, and knurled controls. Similarly, it measures slightly less than 3 inches in either direction and weighs 13.1 ounces, making it an easy travel companion whether shooting stills or video. A metal lens hood and magnetic lens cap are included, adding yet another layer of functional elegance. Its mount is dust and splash resistant, while its front accepts 62mm filters.
Lens Mount: Sony E
Lens Construction: 13 elements in 11 groups
Angle of View: 94.5 Degree (Full Frame) / 70.7 Degree (APS-C)
Diaphragm Blades: 9, rounded
Autofocus Actuator: STM (stepping motor)
Minimum Aperture: f/22
Minimum Focus Distance: 8.7″ (22cm)
Max. Magnification Ratio: 1:6.7
Filter Size: 62mm
Dimensions (Diameter x L): 2.8 x 2.9″ (70 x 72.4mm)
Weight: 13.1 oz (370g)