Comparison of Sigma 17-35mm f/2.8-4 EX DG Aspherical HSM and Tokina 11-16mm f/2.8 AT-X 116 PRO DX

Attribute	Tokina 11-16mm f/2.8 AT-X 116 PRO DX ×	Sigma 17-35mm f/2.8-4 EX DG Aspherical HSM ×
Filter Size (mm)	77	77
Notes	Available AF Mounts: Canon, Nikon and Sony APS-C digital only	Available AF Mounts: [HSM version]: Sigma, Canon, Nikon; [w/o HSM]: Minolta, Pentax
Closest Focus (m)	0.3	0.27
Magnification Ratio (x)	0.09	0.22
Type	Wide Zoom	Wide Zoom
Length (mm)	89.2	88.7
APS Equivalent	1.5x: 16.5 - 24mm; 1.6x: 17.6 - 25.6mm	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 - 16.00	17.00 - 35.00
Brand	Tokina	Sigma
Name	Tokina 11-16mm f/2.8 AT-X 116 PRO DX	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)	82.00 - 104.00	63.40 - 103.70
Lens Construction	13 elements in 11 groups, including 2 SD (Super-low Dispersion) and 2 aspheric elements	16 elements in 13 groups, including 2 aspherical and 1 SLD elements
Diameter (mm)	84	83.5
Focus Details	Internal with One-Touch Focus Clutch mechanism	Internal Focus; HSM with full-time manual override