Comparison of Sigma 10-20mm ƒ/3.5 EX DC HSM and Tokina 12-28mm f/4 AT-X 128 AF PRO DX

Attribute	Tokina 12-28mm f/4 AT-X 128 AF PRO DX ×	Sigma 10-20mm ƒ/3.5 EX DC HSM ×
Filter Size (mm)	77	82
Notes	Available AF Mounts: Canon and Nikon Digital Only. Built-in AF motor for use with all Nikon DSLRs. Included Accessories: Lens Hood	Available AF mounts: Sigma, Canon, Nikon, Sony, Pentax; Included Accessories: Soft Case, Petal-type Hood
Closest Focus (m)	0.25	0.24
Magnification Ratio (x)	0.2	0.15
Type	Wide Zoom	Wide Zoom
Length (mm)	90.2	88.2
APS Equivalent	1.5x: 18 - 42mm;1.6x: 19.2 - 44.8mm	1.5x: 15 - 30mm; 1.6x: 16 - 32mm
Zoom System	Rotary	Rotary
Image Circle	APS-C	Image Circle
Focal Length (mm)	12.00 - 28.00	10.00 - 20.00
Brand	Tokina	Sigma
Name	Tokina 12-28mm f/4 AT-X 128 AF PRO DX	Sigma 10-20mm ƒ/3.5 EX DC HSM
Weight (g)	530	520
Aperture (f)	4.00 - 22.00	3.50 - 22.00
Diaphragm Blades	9	7
Diagonal Angle of View (degree)	54.70 - 99.40	63.80 - 102.40
Lens Construction	14 elements in 12 groups, including 2 aspherical and 2 SD elements	13 elements in 10 groups, including 4 aspherical, 1 SLD and 2 ELD elements
Diameter (mm)	84	87.3
Focus Details	Internal with One-Touch Focus Clutch mechanism; SD-M (Silent Drive-Module)	Internal with HSM