Comparison of Canon EF-S 15-85mm ƒ/3.5-5.6 IS USM and Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM

Attribute	Canon EF-S 15-85mm ƒ/3.5-5.6 IS USM ×	Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM ×
Aperture (f)	3.50 - 38.00	2.80 - 22.00
Filter Size (mm)	72	72
Notes	EF-S lens mount, exclusively for bodies with APS-C sensors. Image Stabilization up to 4-stops.	Image Stabilized. Available AF Mounts: Canon, Nikon, Pentax, Sigma, Sony
Closest Focus (m)	0.35	0.22
Magnification Ratio (x)	0.21	0.37
Zoom System	Rotary	Rotary with lock
Type	Standard Zoom	Standard Zoom
APS Equivalent	24 - 136mm	1.5x: 25.5 - 105mm; 1.6x: 27.2 - 112mm
Diaphragm Blades	7	7
Image Circle	APS-C	APS-C
Focal Length (mm)	15.00 - 85.00	17.00 - 70.00
Brand	Canon	Sigma
Name	Canon EF-S 15-85mm ƒ/3.5-5.6 IS USM	Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM
Weight (g)	575	535
Diaphragm Blades Type	rounded	rounded
Lens Construction	17 elements in 12 groups, including UD and aspherical elements	17 elements in 13 groups, including 1 ELD and 3 aspherical elements
Diagonal Angle of View (degree)	18.40 - 84.50	20.20 - 72.40
Length (mm)	88	88.9
Diameter (mm)	82	79
Focus Details	Inner focusing; full-time manual focus and USM; AF/MF switch	Internal, with Hyper-Sonic Motor; AF/MF switch