Comparison of Canon EF-S 17-55mm f/2.8 IS USM and Sigma 24-70mm f/2.8 EX DG Macro

Attribute	Sigma 24-70mm f/2.8 EX DG Macro ×	Canon EF-S 17-55mm f/2.8 IS USM ×
Filter Size (mm)	82	77
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	Image Stabilization; Included Accessories: Lens Hood EW-83J
Closest Focus (m)	0.4	0.35
Magnification Ratio (x)	0.26	0.17
Type	Standard Zoom	Standard Zoom
Length (mm)	115.5	110.6
APS Equivalent	1.5x: 36 - 105mm; 1.6x: 38.4 - 112mm	27 - 88mm
Zoom System	Rotary	Rotary
Image Circle	35mm	APS-C
Focal Length (mm)	24.00 - 70.00	17.00 - 55.00
Brand	Sigma	Canon
Name	Sigma 24-70mm f/2.8 EX DG Macro	Canon EF-S 17-55mm f/2.8 IS USM
Weight (g)	715	645
Aperture (f)	2.80 - 32.00	2.80 - 22.00
Diaphragm Blades	9	7
Diagonal Angle of View (degree)	34.30 - 84.10	27.80 - 78.50
Lens Construction	14 elements in 13 groups, including 3 aspherical and 2 SLD elements	19 elements in 12 groups
Diameter (mm)	88.6	83.5
Focus Details	Internal with Dual Focus mechanism	USM with full-time manual focusing