Comparison of Canon EF 20-35mm f/3.5-4.5 USM and Tamron AF 19-35mm f/3.5-4.5

Attribute	Canon EF 20-35mm f/3.5-4.5 USM ×	Tamron AF 19-35mm f/3.5-4.5 ×
Filter Size (mm)	77	77
Aperture (f)	3.50 - 27.00	3.50 - 22.00
Closest Focus (m)	0.34	0.5
Magnification Ratio (x)	0.13	0.08
Type	Wide Zoom	Wide Zoom
Focus Details	Inner focusing; full-time manual focus and USM;	Internal
APS Equivalent	32 - 56mm	1.5x: 28.5 - 52.5mm; 1.6x: 30.4 - 56mm
Diameter (mm)	83.5	83.2
Image Circle	35mm	35mm
Focal Length (mm)	20.00 - 35.00	19.00 - 35.00
Brand	Canon	Tamron
Name	Canon EF 20-35mm f/3.5-4.5 USM	Tamron AF 19-35mm f/3.5-4.5
Weight (g)	340	317
Diagonal Angle of View (degree)	63.00 - 94.00	63.00 - 97.00
Diaphragm Blades	5	8
Zoom System	Rotary	Rotary
Length (mm)	68.9	67.7
Notes	-	Available AF Mounts: Canon, Minolta, Nikon
Lens Construction	12 elements in 11 groups	13 elements in 11 groups