Comparison of Canon EF 28-105mm f/3.5-4.5 II USM and Sigma 28-105mm f/2.8-4 DG

Attribute	Sigma 28-105mm f/2.8-4 DG ×	Canon EF 28-105mm f/3.5-4.5 II USM ×
Filter Size (mm)	72	58
Aperture (f)	2.80 - 22.00	3.50 - 27.00
Closest Focus (m)	0.5	0.5
Magnification Ratio (x)	0.18	0.19
Type	Standard Zoom	Standard Zoom
Focus Details	Internal focusing	Inner focusing; full-time manual focus and USM
APS Equivalent	1.5x: 42 - 157.5mm; 1.6x: 44.8 - 168mm	45 - 168mm
Diameter (mm)	77	72
Image Circle	35mm	35mm
Focal Length (mm)	28.00 - 105.00	28.00 - 105.00
Brand	Sigma	Canon
Name	Sigma 28-105mm f/2.8-4 DG	Canon EF 28-105mm f/3.5-4.5 II USM
Weight (g)	405	375
Diagonal Angle of View (degree)	23.30 - 75.40	23.50 - 75.00
Diaphragm Blades	8	7
Zoom System	Rotary	Rotary
Length (mm)	81	75
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	-
Lens Construction	12 elements in 11 groups, including 1 aspherical element	15 elements in 12 groups