Sigma 40mm f/1.4 Art HSM DG

Fixed lens with a non-standard focal length of 40mm and a high aperture of f/1.4. The model is available both in versions for popular SLR mounts (Sigma SA, Nikon F, Canon EF), and in a modification for the Sony E mirrorless system. Surprisingly, the lens turned out to be large and heavy — its body dimensions are 88x131 mm, and it weighs about 2.1 kg. Specific dimensions and weight may vary depending on the mount.

The optical design of the Sigma 40mm f/1.4 Art HSM DG consists of 16 elements in 12 groups. The scheme includes three FLD lenses, three SLD elements, and one aspherical glass (to improve color accuracy and minimize chromatic aberrations). The rendering of impressive bokeh is ensured by a 9-blade rounded diaphragm. The Hyper Sonic Motor ring drive aids in focusing the lens for sharpness. The model features an internal focusing system and a window with a marked focus distance scale (in meters and feet). The lens is compatible with standard round filters with a diameter of 82 mm. Firmware updates and focus adjustments (for SLR versions) can be done through the dedicated Sigma USB Dock.