Comparison of Nikon AF-S TC-17E II 1.7X and Sigma TC-2001 2X Teleconverter

Attribute	Sigma TC-2001 2X Teleconverter ×	Nikon AF-S TC-17E II 1.7X ×
Type	Teleconverter	Teleconverter
Name	Sigma TC-2001 2X Teleconverter	Nikon AF-S TC-17E II 1.7X
Weight (g)	290	250
Image Circle	35mm	35mm
Brand	Sigma	Nikon
Magnification Ratio (x)	2	1.7
Lens Construction	10 elements in 5 groups, including 2 SLD elements	7 elements in 4 groups
Notes	Dust and splash-proof; Available AF Mounts: Canon EF, Nikon F, Sigma SA	Designed exclusively for use with Nikkor AF-S and AF-I lenses.
Diameter (mm)	69.8	66
Focal Length Multiplier	2X that of the master lens	1.7X that of the master lens
Effective Reduction in Aperture	2 f-stops	1.5 f-stop
Length (mm)	48.9	31.5