Comparison of Canon EF 400mm f/2.8L IS USM and Olympus 300mm f/2.8 Zuiko Digital

Attribute	Canon EF 400mm f/2.8L IS USM ×	Olympus 300mm f/2.8 Zuiko Digital ×
Magnification Ratio (x)	0.15	0.15
Filter Size (mm)	52	-
Focus Details	Inner focusing; full-time manual focus and USM	-
Closest Focus (m)	3	2
Lens Construction	17 elements in 13 groups, including 1 flourite and 2 UD elements	13 elements in 11 groups, including 3 ED elements
Length (mm)	349	282
Focal Length (mm)	400.00	300.00
Diagonal Angle of View (degree)	6.20	4.20
Brand	Canon	Olympus
Image Circle	35mm	Image Circle
Name	Canon EF 400mm f/2.8L IS USM	Olympus 300mm f/2.8 Zuiko Digital
Weight (g)	5370	3300
Type	Telephoto Prime	Telephoto Prime
Notes	Image Stabilization	Includes Lens Hood (LH-120) and Lens Case (LSH-1738)
APS Equivalent	640mm	-
Aperture (f)	2.80 - 32.00	2.80 - 22.00
Diaphragm Blades	8	9
35mm Equivalent	-	600mm
Diameter (mm)	163	129