Comparison of Sigma 28-70mm f/2.8-4 DG and Sony SAL-1870 DT 18-70mm f/3.5-5.6

Attribute	Sigma 28-70mm f/2.8-4 DG ×	Sony SAL-1870 DT 18-70mm f/3.5-5.6 ×
Aperture (f)	2.80 - 22.00	3.50 - 36.00
Filter Size (mm)	62	55
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax; Included Accessories: Lens Hood	Included Accessories: SH0006 Lens Hood
Closest Focus (m)	0.5	0.38
Magnification Ratio (x)	0.15	0.25
Diameter (mm)	67.5	66
Type	Standard Zoom	Standard Zoom
APS Equivalent	1.5x: 42 - 105mm; 1.6x: 44.8 - 112mm	27 - 105mm
Diaphragm Blades	8	7
Image Circle	35mm	APS-C
Focal Length (mm)	28.00 - 70.00	18.00 - 70.00
Brand	Sigma	Sony
Name	Sigma 28-70mm f/2.8-4 DG	Sony SAL-1870 DT 18-70mm f/3.5-5.6
Weight (g)	255	235
Diagonal Angle of View (degree)	34.30 - 75.40	23.00 - 76.00
Lens Construction	11 elements in 8 groups, including 1 aspherical element	11 elements in 9 groups, including 1 aspheric and 1 ED glass elements
Zoom System	Rotary	Rotary
Length (mm)	62.5	77
Focus Details	-	Front focusing
Front Element Rotation	-	-