Comparison of Canon EF 28-135mm f/3.5-5.6 IS USM and Sigma 24-135mm f/2.8-4.5 Aspherical IF

Attribute	Sigma 24-135mm f/2.8-4.5 Aspherical IF ×	Canon EF 28-135mm f/3.5-5.6 IS USM ×
Filter Size (mm)	77	72
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	Image Stabilization
Closest Focus (m)	0.5	0.5
Magnification Ratio (x)	0.22	0.19
Type	Standard Zoom	Standard Zoom
Length (mm)	90.9	97
APS Equivalent	1.5x: 36 - 202.5mm; 1.6x: 38.4 - 216mm	45 - 216mm
Zoom System	Rotary	Rotary
Image Circle	35mm	35mm
Focal Length (mm)	24.00 - 135.00	28.00 - 135.00
Brand	Sigma	Canon
Name	Sigma 24-135mm f/2.8-4.5 Aspherical IF	Canon EF 28-135mm f/3.5-5.6 IS USM
Weight (g)	530	540
Aperture (f)	2.80 - 32.00	3.50 - 36.00
Diaphragm Blades	9	6
Diagonal Angle of View (degree)	18.20 - 84.10	18.00 - 75.00
Lens Construction	16 elements in 15 groups, including 2 aspherical and 1 SLD elements	16 elements in 12 groups, including 1 aspherical element
Diameter (mm)	83.6	78
Focus Details	Internal	Inner focusing; full-time manual focus and USM