Comparison of Canon EF 400mm ƒ/2.8L IS II USM and Tamron SP AF 300mm f/2.8 LD IF

Attribute	Canon EF 400mm ƒ/2.8L IS II USM ×	Tamron SP AF 300mm f/2.8 LD IF ×
Magnification Ratio (x)	0.17	0.141
Filter Size (mm)	52	43
Focus Details	Inner focusing; Ultra-sonic Motor (USM), AF/PF/MF switch, Focus Preset, Range Limiter	Internal; Focus ring slides back and forth to switch between AF and MF
Closest Focus (m)	1.7	2.5
Lens Construction	16 elements in 12 groups	10 elements in 7 groups, including 2 LD elements
Length (mm)	343	215.9
Focal Length (mm)	400.00	300.00
Diaphragm Blades Type	rounded	-
Brand	Canon	Tamron
Image Circle	35mm	35mm
Name	Canon EF 400mm ƒ/2.8L IS II USM	Tamron SP AF 300mm f/2.8 LD IF
Weight (g)	3900	2800
Type	Telephoto Prime	Telephoto Prime
Notes	Image Stabilization (4-stops); Included Accessories: lens hood and hard case.	Available AF Mounts: Canon, Minolta, Nikon; Included Accessories: Lens Hood, Case
APS Equivalent	640mm	1.5x: 450mm; 1.6x: 480mm
Aperture (f)	2.80 - 32.00	2.80 - 32.00
Diaphragm Blades	9	9
Diagonal Angle of View (degree)	6.20	8.00
Diameter (mm)	163	120