Comparison of Sigma 17-35mm f/2.8-4 EX DG Aspherical HSM and Tokina 11-20mm f/2.8 AT-X PRO DX SD

Attribute	Tokina 11-20mm f/2.8 AT-X PRO DX SD ×	Sigma 17-35mm f/2.8-4 EX DG Aspherical HSM ×
Filter Size (mm)	82	77
Notes	Available AF Mounts: Canon EF, Nikon F (lens has focus motor); Included Accessories: BH-821 Lens Hood	Available AF Mounts: [HSM version]: Sigma, Canon, Nikon; [w/o HSM]: Minolta, Pentax
Closest Focus (m)	0.28	0.27
Magnification Ratio (x)	0.12	0.22
Type	Wide Zoom	Wide Zoom
Length (mm)	92	88.7
APS Equivalent	1.5x: 16.5 - 30mm; 1.6x: 17.6 - 32mm	1.5x: 25.5 - 52.5mm; 1.6x: 27.2 - 56mm
Zoom System	Rotary	Rotary
Image Circle	APS-C	35mm
Focal Length (mm)	11.00 - 20.00	17.00 - 35.00
Brand	Tokina	Sigma
Name	Tokina 11-20mm f/2.8 AT-X PRO DX SD	Sigma 17-35mm f/2.8-4 EX DG Aspherical HSM
Weight (g)	560	560
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades	9	8
Diagonal Angle of View (degree)	72.70 - 104.50	63.40 - 103.70
Lens Construction	14 elements in 12 groups, including 2 SD (Super-low Dispersion) and 3 aspheric elements	16 elements in 13 groups, including 2 aspherical and 1 SLD elements
Diameter (mm)	89	83.5
Focus Details	Internal with One-Touch Focus Clutch mechanism	Internal Focus; HSM with full-time manual override