Comparison of Sigma APO 300mm ƒ/2.8 EX DG HSM and Tamron SP AF 300mm f/2.8 LD IF

Attribute	Tamron SP AF 300mm f/2.8 LD IF ×	Sigma APO 300mm ƒ/2.8 EX DG HSM ×
Aperture (f)	2.80 - 32.00	2.80 - 32.00
Filter Size (mm)	43	46
Notes	Available AF Mounts: Canon, Minolta, Nikon; Included Accessories: Lens Hood, Case	Available AF Mounts: [HSM version]: Sigma, Canon, Nikon; [w/o HSM]: Minolta, Pentax
Closest Focus (m)	2.5	2.5
Magnification Ratio (x)	0.141	0.13
Type	Telephoto Prime	Telephoto Prime
Focus Details	Internal; Focus ring slides back and forth to switch between AF and MF	Internal; HSM with full-time manual override
APS Equivalent	1.5x: 450mm; 1.6x: 480mm	1.5x: 450mm; 1.6x: 480mm
Diaphragm Blades	9	9
Image Circle	35mm	35mm
Focal Length (mm)	300.00	300.00
Brand	Tamron	Sigma
Name	Tamron SP AF 300mm f/2.8 LD IF	Sigma APO 300mm ƒ/2.8 EX DG HSM
Weight (g)	2800	2400
Diagonal Angle of View (degree)	8.00	8.20
Length (mm)	215.9	214.5
Diameter (mm)	120	119
Lens Construction	10 elements in 7 groups, including 2 LD elements	11 elements in 9 groups, including 2 ELD elements