Comparison of Canon EF-S 17-85mm f/4-5.6 IS USM and Sigma 17-70mm f/2.8-4.5 DC Macro

Attribute	Sigma 17-70mm f/2.8-4.5 DC Macro ×	Canon EF-S 17-85mm f/4-5.6 IS USM ×
Filter Size (mm)	72	67
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	EF-S lens mount, exclusively for EOS 20D, Digital Rebel, and newer bodies with APS-C sensors.
Closest Focus (m)	0.2	0.35
Magnification Ratio (x)	0.43	0.2
Type	Standard Zoom	Standard Zoom
Length (mm)	82.5	92
APS Equivalent	1.5x: 25.5 - 105mm; 1.6x: 27.2 - 112mm	27 - 136mm
Zoom System	Rotary with lock	Rotary
Image Circle	APS-C	APS-C
Focal Length (mm)	17.00 - 70.00	17.00 - 85.00
Brand	Sigma	Canon
Name	Sigma 17-70mm f/2.8-4.5 DC Macro	Canon EF-S 17-85mm f/4-5.6 IS USM
Weight (g)	455	475
Aperture (f)	2.80 - 22.00	4.00 - 32.00
Diaphragm Blades	7	6
Diagonal Angle of View (degree)	20.20 - 72.40	18.40 - 78.50
Lens Construction	15 elements in 12 groups, including 1 SLD and 2 aspherical elements	17 elements in 12 groups, including 1 aspherical element
Diameter (mm)	79	78
Focus Details	Internal	Inner focusing; full-time manual focus and USM