Comparison of Canon EF 400mm f/4 DO IS USM and Pentax SMC P-FA 80-200mm f/2.8 ED IF

Attribute	Canon EF 400mm f/4 DO IS USM ×	Pentax SMC P-FA 80-200mm f/2.8 ED IF ×
Filter Size (mm)	52	77
Notes	Image Stabilization	Included Accessories: Lens Hood
Closest Focus (m)	3.5	1.4
Magnification Ratio (x)	0.12	0.19
Type	Telephoto Prime	Telephoto Zoom
Focus Details	Inner focusing; full-time manual focus and USM	Internal
APS Equivalent	640mm	120 - 300mm
Diameter (mm)	128	86.4
Image Circle	35mm	35mm
Focal Length (mm)	400.00	80.00 - 200.00
Brand	Canon	Pentax
Name	Canon EF 400mm f/4 DO IS USM	Pentax SMC P-FA 80-200mm f/2.8 ED IF
Weight (g)	1940	1571
Aperture (f)	4.00 - 32.00	2.80 - 32.00
Diaphragm Blades	8	-
Diagonal Angle of View (degree)	6.20	12.50 - 30.50
Length (mm)	233	191
Zoom System	-	Rotary
Lens Construction	17 elements in 13 groups, including 1 flourite and 1 DO element	16 elements in 13 groups, including 1 ED element