Comparison of Canon EF 16-35mm f/2.8L USM and Tokina 20-35mm f/2.8 AT-X 235 AF PRO

Attribute	Canon EF 16-35mm f/2.8L USM ×	Tokina 20-35mm f/2.8 AT-X 235 AF PRO ×
Magnification Ratio (x)	0.22	-
Filter Size (mm)	77	77
Focus Details	Inner focusing; full-time manual focus and USM;	Internal with One-Touch Focus Clutch mechanism
Closest Focus (m)	0.28	0.25
Lens Construction	13 elements in 10 groups, including 3 aspherical and 2 UD elements	15 elements in 11 groups, including 2 aspherical elements
Length (mm)	103	85.5
Focal Length (mm)	16.00 - 35.00	20.00 - 35.00
Diagonal Angle of View (degree)	63.00 - 108.20	63.20 - 93.60
Brand	Canon	Tokina
Image Circle	35mm	35mm
Name	Canon EF 16-35mm f/2.8L USM	Tokina 20-35mm f/2.8 AT-X 235 AF PRO
Weight (g)	600	585
Type	Wide Zoom	Wide Zoom
Notes	Includes Hood EW-83E, Lens Case LP 1319	Available AF Mounts: Canon, Minolta, Nikon; Included Accessories: Lens Hood, Fitted Soft Case
APS Equivalent	26 - 56mm	1.5x: 30 - 52.5mm; 1.6x: 32 - 56mm
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades	7	8
Zoom System	Rotary	Rotary
Diameter (mm)	83.5	84