Comparison of Pentax 50mm f/1.4 SDM AW HD D FA* and Sigma 40mm f/1.4 DG HSM Art

Attribute	Sigma 40mm f/1.4 DG HSM Art ×	Pentax 50mm f/1.4 SDM AW HD D FA* ×
Filter Size (mm)	82	72
Notes	Available AF Mounts: Canon EF, Nikon F, Sigma SA and Sony E; Compatible with Sigma's USB Dock and Mount Conversion Service	Dustproof, weather-resistant construction; Electromagnetic diaphragm
Closest Focus (m)	0.4	0.4
Magnification Ratio (x)	0.15	0.18
Type	Wide Prime	Standard Prime
Focus Details	HSM (Hypersonic Motor) with full-time manual focus override	Ring-type SDM (Supersonic Direct-drive Motor)
APS Equivalent	1.5x: 60mm; 1.6x: 64mm	75mm
Diameter (mm)	87.8	80
Image Circle	35mm	35mm
Focal Length (mm)	40.00	50.00
Brand	Sigma	Pentax
Name	Sigma 40mm f/1.4 DG HSM Art	Pentax 50mm f/1.4 SDM AW HD D FA*
Weight (g)	1200	910
Aperture (f)	1.40 - 16.00	1.40 - 16.00
Diaphragm Blades	9	9
Diagonal Angle of View (degree)	56.80	47.00
Length (mm)	131	106
Diaphragm Blades Type	rounded	-
Lens Construction	16 elements in 12 groups, including 1 aspherical, 3 FLD and 3 SLD elements	15 elements in 9 groups, including 3 SLD (Super Low Dispersion) glass elements and 1 aspherical element