Comparison of Canon EF 400mm ƒ/4 DO IS II USM and Sigma APO 120-300mm f/2.8 EX IF HSM

Attribute	Canon EF 400mm ƒ/4 DO IS II USM ×	Sigma APO 120-300mm f/2.8 EX IF HSM ×
Aperture (f)	4.00 - 32.00	2.80 - 32.00
Filter Size (mm)	52	105
Notes	Image Stabilization (4 stops); Weather-sealed construction	Available AF Mounts: Sigma, Canon, Nikon
Closest Focus (m)	3.3	1.5
Magnification Ratio (x)	0.13	0.12
Diameter (mm)	128	112.8
Type	Telephoto Prime	Telephoto Zoom
APS Equivalent	640mm	1.5x: 180 - 450mm; 1.6x: 192 - 480mm
Diaphragm Blades	9	9
Image Circle	35mm	35mm
Focal Length (mm)	400.00	120.00 - 300.00
Brand	Canon	Sigma
Name	Canon EF 400mm ƒ/4 DO IS II USM	Sigma APO 120-300mm f/2.8 EX IF HSM
Weight (g)	2100	2600
Diaphragm Blades Type	rounded	-
Lens Construction	18 elements in 12 groups, including 1 aspheric and 1 UD element; Newly-developed gapless dual-layer diffractive optical (DO) elements	18 elements in 16 groups, including 4 SLD elements
Diagonal Angle of View (degree)	6.20	8.20 - 20.40
Length (mm)	233	271
Zoom System	-	Rotary; Internal
Focus Details	Inner focusing; full-time manual focus and ring USM	Internal; HSM with full-time manual override