Comparison of Canon EF 500mm ƒ/4L IS II USM and Canon EF 400mm f/2.8L IS III USM

Attribute	Canon EF 500mm ƒ/4L IS II USM ×	Canon EF 400mm f/2.8L IS III USM ×
Filter Size (mm)	52	52
Notes	Image Stabilization (up to 4-stops), includes new Mode 3 that activates IS only when the shutter button is fully pressed.	Image Stabilization (up to 5-stops of correction); Dust- and water-resistant construction; Detachable, rotatable tripod collar.
Closest Focus (m)	3.7	2.5
Magnification Ratio (x)	0.15	0.17
Type	Telephoto Prime	Telephoto Prime
Focus Details	Inner focusing; full-time manual focus and USM	Inner focusing; full-time manual focus and Ring USM; Customizable Electronic Focusing Ring; 2 Focus Presets;
APS Equivalent	800mm	640mm
Diameter (mm)	146	163
Image Circle	35mm	35mm
Focal Length (mm)	500.00	400.00
Brand	Canon	Canon
Name	Canon EF 500mm ƒ/4L IS II USM	Canon EF 400mm f/2.8L IS III USM
Weight (g)	3190	2840
Aperture (f)	4.00 - 32.00	2.80 - 32.00
Diaphragm Blades	9	9
Diagonal Angle of View (degree)	5.00	6.20
Length (mm)	383	343
Diaphragm Blades Type	-	circular
Lens Construction	16 elements in 12 groups; Fluorite: G2 and G4, UD Lens: None	17 elements in 13 groups, including 2 fluorite elements and one super UD element; Super Spectra Coating (SSC); Air Sphere Coating (ASC)