Comparison of Pentax 18-270mm f/3.5-6.3 ED SDM SMC DA and Tamron 16-300mm f/3.5-6.3 Di II VC PZD Macro (Model B016)

Attribute	Tamron 16-300mm f/3.5-6.3 Di II VC PZD Macro (Model B016) ×	Pentax 18-270mm f/3.5-6.3 ED SDM SMC DA ×
Aperture (f)	3.50 - 40.00	3.50 - 45.00
Filter Size (mm)	67	62
Notes	Includes flower-shaped lens hood. Available AF mounts: Canon EF-S, Nikon F, Sony A; VC Image Stabilization; Sony version does not include VC.	Autofocus supported on K10D and later bodies. Optional Accessories: PH-RBD lens hood, S80-120 case.
Closest Focus (m)	0.39	0.45
Magnification Ratio (x)	0.34	0.26
Zoom System	Rotary	Rotary, with lock switch
Type	Standard Zoom	Standard Zoom
APS Equivalent	1.5x: 24 - 450mm 1.6x: 25.6 - 480mm	27.5 - 414mm
Diaphragm Blades	7	7
Image Circle	APS-C	APS-C
Focal Length (mm)	16.00 - 300.00	18.00 - 270.00
Brand	Tamron	Pentax
Name	Tamron 16-300mm f/3.5-6.3 Di II VC PZD Macro (Model B016)	Pentax 18-270mm f/3.5-6.3 ED SDM SMC DA
Weight (g)	540	453
Diaphragm Blades Type	rounded	rounded
Lens Construction	16 elements in 12 groups including 1 Hybrid Aspherical, two LD (Low Dispersion), 1 XR (Extra Refractive index), 1 UXR (Ultra-Extra Refractive Index)	16 elements in 13 groups, including 2 ED and 2 aspherical elements
Diagonal Angle of View (degree)	5.30 - 82.20	6.00 - 76.00
Length (mm)	99.5	89
Diameter (mm)	75	75.8
Focus Details	Internal with Piezo Drive motor; Full-time manual focus function	Internal with supersonic AF motor (SDM)