Comparison of Canon EF 20mm f/2.8 USM and Carl Zeiss 18mm f/3.5 Distagon T* 3.5/18

Attribute	Carl Zeiss 18mm f/3.5 Distagon T* 3.5/18 ×	Canon EF 20mm f/2.8 USM ×
Diagonal Angle of View (degree)	99.00	94.00
Filter Size (mm)	82	72
Aperture (f)	3.50 - 22.00	2.80 - 22.00
Closest Focus (m)	0.3	0.25
Magnification Ratio (x)	0.083	0.14
Type	Wide Prime	Wide Prime
Focus Details	Manual focus only	Inner focusing; full-time manual focus and USM
APS Equivalent	1.5x: 27mm	32mm
Diaphragm Blades	-	6
Image Circle	35mm	35mm
Focal Length (mm)	18.00	20.00
Brand	Carl-zeiss	Canon
Name	Carl Zeiss 18mm f/3.5 Distagon T* 3.5/18	Canon EF 20mm f/2.8 USM
Weight (g)	470	405
Diameter (mm)	87	71
Length (mm)	84	77
Notes	Available SLR mounts: Canon EF (ZE), Nikon F (ZF, ZF.2), Pentax K (ZK). Lens shade included. Nikon ZF.2 version includes CPU interface for autoexposu	-
Lens Construction	13 elements in 11 groups	11 elements in 9 groups