Comparison of Canon EF-S 17-85mm f/4-5.6 IS USM and Tamron SP AF 28-75mm f/2.8 XR Di LD Aspherical IF

Attribute	Tamron SP AF 28-75mm f/2.8 XR Di LD Aspherical IF ×	Canon EF-S 17-85mm f/4-5.6 IS USM ×
Filter Size (mm)	67	67
Notes	Available mounts: Canon, Minolta-D, Nikon-D, Pentax; Includes petal type lens hood.	EF-S lens mount, exclusively for EOS 20D, Digital Rebel, and newer bodies with APS-C sensors.
Closest Focus (m)	0.33	0.35
Magnification Ratio (x)	0.26	0.2
Type	Standard Zoom	Standard Zoom
Length (mm)	92	92
APS Equivalent	1.5x: 42 - 112.5mm; 1.6x: 44.8 - 120mm	27 - 136mm
Zoom System	Rotary, telescoping	Rotary
Image Circle	Image Circle	APS-C
Focal Length (mm)	28.00 - 75.00	17.00 - 85.00
Brand	Tamron	Canon
Name	Tamron SP AF 28-75mm f/2.8 XR Di LD Aspherical IF	Canon EF-S 17-85mm f/4-5.6 IS USM
Weight (g)	510	475
Aperture (f)	2.80 - 32.00	4.00 - 32.00
Diaphragm Blades	7	6
Diagonal Angle of View (degree)	32.00 - 75.00	18.40 - 78.50
Lens Construction	16 elements in 14 groups, including one Extra Refractive Index element, four Aspherical elements and three Low Dispersion elements	17 elements in 12 groups, including 1 aspherical element
Diameter (mm)	73	78
Focus Details	Internal	Inner focusing; full-time manual focus and USM