Comparison of Olympus 300mm f/4.0 IS Pro ED M.Zuiko Digital and Tamron 70-200mm f/2.8 Di LD IF Macro SP AF

Attribute	Olympus 300mm f/4.0 IS Pro ED M.Zuiko Digital ×	Tamron 70-200mm f/2.8 Di LD IF Macro SP AF ×
Aperture (f)	4.00 - 22.00	2.80 - 32.00
Diaphragm Blades Type	rounded	-
Filter Size (mm)	77	77
Notes	Built-in image stabilization CIPA rated for 4.0 stops, 6.0 stops when combined with Olympus body IS; Dust and splash-proof	Available mounts: Canon, Nikon, Pentax, Sony; Included accessories: Petal-shaped lens hood
APS Equivalent	-	1.5x: 105 - 300mm; 1.6x: 112 - 320mm
Type	Telephoto Prime	Telephoto Zoom
Diaphragm Blades	9	9
35mm Equivalent	600mm	-
Image Circle	Image Circle	35mm
Focal Length (mm)	300.00	70.00 - 200.00
Brand	Olympus	Tamron
Name	Olympus 300mm f/4.0 IS Pro ED M.Zuiko Digital	Tamron 70-200mm f/2.8 Di LD IF Macro SP AF
Weight (g)	1270	1100
Diagonal Angle of View (degree)	4.10	12.30 - 34.30
Lens Construction	17 elements in 10 groups, including 3 Super ED, 1 Extra-High Refractive index lens and 3 High Refractive index elements; ZERO coating	18 elements in 13 groups, including 3 LD (low dispersion) elements
Diameter (mm)	92.5	89.5
Length (mm)	227	194.3
Focus Details	-	Internal Focusing; One-touch AF/MF Switchover mechanism (for Canon and Nikon only)
Magnification Ratio (x)	0.24	0.32
Zoom System	-	Rotary
Closest Focus (m)	1.4	0.95