Comparison of Sigma 28-200mm f/3.5-5.6 DG Macro and Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical IF

Attribute	Sigma 28-200mm f/3.5-5.6 DG Macro ×	Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical IF ×
Aperture (f)	3.50 - 22.00	3.50 - 22.00
Filter Size (mm)	62	62
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax; Include Accessories: Lens Hood	Available mounts: Canon, Minolta, Nikon, Pentax. Includes petal type hood.
Closest Focus (m)	0.48	0.45
Magnification Ratio (x)	0.26	0.27
Diameter (mm)	70	73.8
Type	Standard Zoom	Standard Zoom
APS Equivalent	1.5x: 42 - 300mm; 1.6x: 44.8 - 320mm	1.5x: 27 - 300mm; 1.6x: 28.8 - 320mm
Diaphragm Blades	8	7
Image Circle	35mm	Image Circle
Focal Length (mm)	28.00 - 200.00	18.00 - 200.00
Brand	Sigma	Tamron
Name	Sigma 28-200mm f/3.5-5.6 DG Macro	Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical IF
Weight (g)	400	398
Diagonal Angle of View (degree)	12.30 - 75.40	7.00 - 75.00
Lens Construction	16 elements in 14 groups, including 2 aspherical elements	15 elements in 13 groups, with low dispersion, aspherical and extra reffractive index elements
Zoom System	Rotary with lock	Rotating, Telescoping
Length (mm)	77.7	83.7
Front Element Rotation	-	-
Focus Details	Internal	Internal focusing system