Comparison of Canon EF 400mm f/5.6L USM and Sigma APO 100-300mm f/4 EX IF HSM

Attribute	Sigma APO 100-300mm f/4 EX IF HSM ×	Canon EF 400mm f/5.6L USM ×
Filter Size (mm)	82	77
Notes	Available AF Mounts: [100-300mm F4 APO EX IF HSM]: Sigma, Canon, Nikon; [100-300mm APO F4 EX IF]: Minolta, Pentax	Built-in hood; detachable tripod mount
Closest Focus (m)	1.8	3.5
Magnification Ratio (x)	0.2	0.12
Type	Telephoto Zoom	Telephoto Prime
Focus Details	Internal; HSM with full-time manual override	Inner focusing; full-time manual focus and USM
APS Equivalent	1.5x: 150 - 450mm; 1.6x: 160 - 480mm	640mm
Diameter (mm)	92.4	90
Image Circle	35mm	35mm
Focal Length (mm)	100.00 - 300.00	400.00
Brand	Sigma	Canon
Name	Sigma APO 100-300mm f/4 EX IF HSM	Canon EF 400mm f/5.6L USM
Weight (g)	1440	1250
Aperture (f)	4.00 - 32.00	5.60 - 32.00
Diaphragm Blades	9	8
Diagonal Angle of View (degree)	8.20 - 24.40	6.20
Length (mm)	226.5	256
Zoom System	Rotary; Internal	-
Lens Construction	16 elements in 14 groups, including 4 SLD elements	7 elements in 6 groups, including 1 UD and 1 S-UD element