Comparison of NIKKOR Z 20mm f/1.8 S and Sigma 20mm f/1.8 EX DG Aspherical RF

Attribute	Sigma 20mm f/1.8 EX DG Aspherical RF ×	NIKKOR Z 20mm f/1.8 S ×
Aperture (f)	1.80 - 22.00	1.80 - 16.00
Filter Size (mm)	82	77
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	Dustproof and splashproof construction
Closest Focus (m)	0.2	0.2
Magnification Ratio (x)	0.25	0.19
Diameter (mm)	88.6	84.5
Focus Details	Internal (Rear Focus) with Dual Focus mechanism	STM (Stepping Motor)
Focal Length (mm)	20.00	20.00
Diaphragm Blades	9	9
Brand	Sigma	Nikon
Image Circle	35mm	35mm (Z Mount)
Name	Sigma 20mm f/1.8 EX DG Aspherical RF	NIKKOR Z 20mm f/1.8 S
Weight (g)	520	505
Type	Wide Prime	Wide-angle prime
Diaphragm Blades Type	-	rounded
Lens Construction	13 elements in 11 groups, including 2 aspherical elements	14 elements in 11 groups, including 3 ED elements and 2 aspherical elements; Nano Crystal Coating.
Diagonal Angle of View (degree)	94.50	94.00
Length (mm)	89.5	108.5
APS Equivalent	1.5x: 30mm; 1.6x: 32mm	-
35mm Equivalent	-	20mm