Comparison of Canon EF 17-40mm f/4L USM and Nikon 12-24mm f/4G ED-IF AF-S DX Nikkor

Attribute	Canon EF 17-40mm f/4L USM ×	Nikon 12-24mm f/4G ED-IF AF-S DX Nikkor ×
Filter Size (mm)	77	77
Notes	Dust and moisture resistant	DX Nikkor for use with Nikon Digital SLR models only. Lens hood, case included.
Closest Focus (m)	0.28	0.3
Magnification Ratio (x)	0.24	0.12
Type	Wide Zoom	Wide Zoom
Length (mm)	96.8	90
APS Equivalent	27 - 64mm	18 - 36mm
Zoom System	Rotary	Rotary
Image Circle	35mm	APS-C
Focal Length (mm)	17.00 - 40.00	12.00 - 24.00
Brand	Canon	Nikon
Name	Canon EF 17-40mm f/4L USM	Nikon 12-24mm f/4G ED-IF AF-S DX Nikkor
Weight (g)	500	485
Aperture (f)	4.00 - 22.00	4.00 - 22.00
Diaphragm Blades	7	7
Diagonal Angle of View (degree)	57.50 - 104.00	61.00 - 99.00
Lens Construction	12 elements in 9 groups, including 3 aspherical elements and 1 S-UD element	11 elements in 7 groups, including 2 ED elements and 3 aspherical elements
Diameter (mm)	83.5	81
Focus Details	Inner focusing; full-time manual focus and USM;	Internal; AF-S "Silent Wave" motor