Comparison of Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM Contemporary and Sigma 28-70mm f/2.8 EX DG

Attribute	Sigma 28-70mm f/2.8 EX DG ×	Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM Contemporary ×
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	Image Stabilized (up to 4 stops); Available AF Mounts: Canon, Nikon, Sigma, Pentax, Sony; Accessory: lens hood LH780-03.
Magnification Ratio (x)	0.23	0.34
Filter Size (mm)	67	72
Length (mm)	87.2	82
Closest Focus (m)	0.33	0.22
Diagonal Angle of View (degree)	34.30 - 75.40	22.90 - 79.70
Focus Details	-	Internal, with Hyper-Sonic Motor; AF/MF switch
Focal Length (mm)	28.00 - 70.00	17.00 - 70.00
APS Equivalent	1.5x: 42 - 105mm; 1.6x: 44.8 - 112mm	1.5x: 25.5 - 105mm; 1.6x: 27.2 - 112mm
Brand	Sigma	Sigma
Image Circle	35mm	APS-C
Name	Sigma 28-70mm f/2.8 EX DG	Sigma 17-70mm ƒ/2.8-4 DC Macro OS HSM Contemporary
Weight (g)	510	470
Type	Standard Zoom	Standard Zoom
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diaphragm Blades	9	7
Diaphragm Blades Type	-	rounded
Lens Construction	14 elements in 12 groups, including 4 aspherical and 2 SLD elements	16 elements in 14 groups, including FLD, SLD, and 3 aspherical elements
Zoom System	Rotary with lock	Rotary with lock
Diameter (mm)	74	79