Comparison of Canon EF 200-400mm f/4L IS USM Extender 1.4X and Sigma APO 120-300mm f/2.8 EX IF HSM

Attribute	Canon EF 200-400mm f/4L IS USM Extender 1.4X ×	Sigma APO 120-300mm f/2.8 EX IF HSM ×
Notes	Built-in 1.4x extender (8 elements in 4 groups) switches to 280-560mm f/5.6 lens with 0.21x / 1.48 magnification ratio; 4-stop Image Stabilization	Available AF Mounts: Sigma, Canon, Nikon
Magnification Ratio (x)	0.15	0.12
Filter Size (mm)	52	105
Length (mm)	366	271
Closest Focus (m)	2	1.5
Diagonal Angle of View (degree)	6.20 - 12.00	8.20 - 20.40
Focus Details	Inner focusing; Full-time manual focus and ring USM; Ring USM, High-speed CPU and optimized AF algorithms; Power Focus mode; Focus Limiter	Internal; HSM with full-time manual override
Focal Length (mm)	200.00 - 400.00	120.00 - 300.00
APS Equivalent	320 - 640mm	1.5x: 180 - 450mm; 1.6x: 192 - 480mm
Brand	Canon	Sigma
Image Circle	35mm	35mm
Name	Canon EF 200-400mm f/4L IS USM Extender 1.4X	Sigma APO 120-300mm f/2.8 EX IF HSM
Weight (g)	3620	2600
Type	Telephoto Zoom	Telephoto Zoom
Aperture (f)	4.00 - 32.00	2.80 - 32.00
Diaphragm Blades	9	9
Diaphragm Blades Type	circular	-
Lens Construction	25 elements in 20 groups (incl. 1 rear filter); one fluorite and four UD lens elements	18 elements in 16 groups, including 4 SLD elements
Zoom System	Rotating	Rotary; Internal
Diameter (mm)	128	112.8