Comparison of Canon EF 70-200mm f/4L IS II USM and Pentax SMC DA* 50-135mm f/2.8 ED AL IF SDM

Attribute	Canon EF 70-200mm f/4L IS II USM ×	Pentax SMC DA* 50-135mm f/2.8 ED AL IF SDM ×
Notes	Image stabilization with up to 5.0 stops of correction (CIPA); Dust and moisture resistant.	Included Accessories: Lens Hood
Magnification Ratio (x)	0.27	0.17
Filter Size (mm)	72	67
Length (mm)	176	136
Closest Focus (m)	1	1
Diagonal Angle of View (degree)	12.00 - 34.00	11.90 - 31.50
Focus Details	Internal; Ultrasonic Motor (USM) with full-time manual focus; Focus limit switch	Internal with "Quick Shift" AF/MF mechanism
Focal Length (mm)	70.00 - 200.00	50.00 - 135.00
APS Equivalent	112 - 320mm	76.5 - 207mm
Brand	Canon	Pentax
Image Circle	35mm	APS-C
Name	Canon EF 70-200mm f/4L IS II USM	Pentax SMC DA* 50-135mm f/2.8 ED AL IF SDM
Weight (g)	780	685
Type	Telephoto Zoom	Telephoto Zoom
Aperture (f)	4.00 - 32.00	2.80 - 22.00
Diaphragm Blades	9	9
Diaphragm Blades Type	rounded	-
Lens Construction	20 elements in 15 groups, including 1 flourite element and 2 UD elements; Air Sphere coating; Fluorine coating	18 elements in 14 groups, including 3 ED elements
Zoom System	Rotary	Rotary
Diameter (mm)	80	76.5