Lenses comparison


Manufacturer	Sigma	Sigma	Sigma	Tamron
Model	18-50 mm f/2.8-4.5 DC OS HSM	18-50 mm f/2.8 EX DC Macro	17-70 mm f/2.8-4.5 DC Macro	SP AF 17-50 mm f/2.8 XR Di II LD Aspherical (IF)
Lenst style	Universal zoom	Universal zoom	Universal zoom	Universal zoom
Focal length	18 - 50 mm	18 - 50 mm	17 - 70 mm	17 - 50 mm
Maximum aperture	f/2.8 - 4.5	f/2.8	f/2.8 - 4.5	f/2.8
Angle of view	69.3 - 27.9 ^o	69.3 - 27.9 ^o	72.4 - 20.2 ^o	78.75 - 31.18 ^o
Closest focusing distance	0.3 m	0.2 m	0.2 m	0.27 m
Maximum magnification	1:4.1	3	1:2.3	1:4.5
Minimum aperture	22	22	22	32
Diaphragm blades	7	7	7	7
Auto focus type	HSM	AF	AF	AF
Lens Construction	16 elements / 12 group	15 elements / 13 group	15 elements / 12 group	16 elements / 13 group
Filter diameter	67 mm	72 mm	72 mm	67 mm
Macro Yes/No	No	Yes	Yes	No
Stabilization	Yes	No	No	No
Available mounts	Nikon F Sony A / Minolta Sigma Pentax K Canon EF-S	Nikon F Sigma Pentax K Four Thirds Canon EF-S	Nikon F Sony A / Minolta Sigma Pentax K Canon EF-S	Nikon F Sony A / Minolta Pentax K Canon EF-S
Dimensions	74 x 88.6 mm	85.8 x 79 mm	79 x 82.5 mm	74 x 81.7 mm
Weight	395 g	450 g	455 g	434 g
Additional information		Special Low Dispersion (SLD) Lenses and Extraordinary Low Dispersion (ELD) Lenses inside Marketed September 2006
Score [max 5.00]	3.97 (10)	4.00 (7)	4.05 (14)	4.31 (27)
Our Review	Review			Review