Comparison of Sigma 12-24mm f/4.5-5.6 II DG HSM and Tamron F AF 2X

Attribute	Sigma 12-24mm f/4.5-5.6 II DG HSM ×	Tamron F AF 2X ×
Type	Wide Zoom	Teleconverter
Brand	Sigma	Tamron
Name	Sigma 12-24mm f/4.5-5.6 II DG HSM	Tamron F AF 2X
Focal Length (mm)	12.00 - 24.00	-
Image Circle	35mm	35mm
Diameter (mm)	87	66.7
APS Equivalent	1.5x: 18 - 36mm; 1.6x: 19.2 - 38.4mm	-
Focus Details	Internal; HSM with full-time manual override	-
Lens Construction	17 elements in 13 groups, including 1 hybrid aspherical, 1 SLD and 4 FLD elements	4 elements in 4 groups
Magnification Ratio (x)	0.16	2
Closest Focus (m)	0.28	-
Notes	Planned AF Mounts: Nikon, Canon, Pentax, Sigma, Sony. Nikon mounts do not have an aperture ring. Some functions may not work depending on the camera	Available AF Mounts: Canon, Minolta, Nikon, Pentax
Length (mm)	120.2	26
Zoom System	Rotary	-
Effective Reduction in Aperture	-	2 f-stops
Diaphragm Blades	6	-
Focal Length Multiplier	-	2X that of the master lens
Aperture (f)	0.60 - 22.00	-