Comparison of Pentax SMC P-FA 100-300mm f/4.7-5.8 and Vivitar 100-300mm f/5.6-6.7 Series 1 AF

Attribute	Vivitar 100-300mm f/5.6-6.7 Series 1 AF ×	Pentax SMC P-FA 100-300mm f/4.7-5.8 ×
Name	Vivitar 100-300mm f/5.6-6.7 Series 1 AF	Pentax SMC P-FA 100-300mm f/4.7-5.8
Weight (g)	437	411
Image Circle	35mm	35mm
Brand	Vivitar	Pentax
APS Equivalent	1.5x: 150 - 450mm;1.6x: 160 - 480mm	150 - 450mm
Focal Length (mm)	100.00 - 300.00	100.00 - 300.00
Closest Focus (m)	1.5	1.5
Diameter (mm)	72	71
Filter Size (mm)	55	58
Magnification Ratio (x)	0.25	0.26
Aperture (f)	5.60 - 32.00	4.70 - 32.00
Diagonal Angle of View (degree)	8.20 - 24.00	8.20 - 24.50
Zoom System	Push-Pull	Rotary
Type	Telephoto Zoom	Telephoto Zoom
Lens Construction	10 elements in 8 groups	11 elements in 9 groups
Notes	Available AF mounts: Canon, Minolta, Nikon, Pentax	-
Length (mm)	137.5	130