Comparison of Pentax SMC P-FA 28-70mm f/2.8 and Tamron SP 24-70mm ƒ/2.8 Di VC USD (Model A007)

Attribute	Tamron SP 24-70mm ƒ/2.8 Di VC USD (Model A007) ×	Pentax SMC P-FA 28-70mm f/2.8 ×
Zoom System	Rotary	Rotary
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Diagonal Angle of View (degree)	34.30 - 84.00	34.50 - 75.00
Filter Size (mm)	82	67
Notes	VC image stabilization. Available mounts: Canon, Nikon, Sony. Includes petal type lens hood.	Included Accessories: Lens Hood and Case
Focus Details	Internal with USD (Ultrasonic Silent Drive), continuous manual mechanism	-
Type	Standard Zoom	Standard Zoom
APS Equivalent	1.5x: 36 - 105mm; 1.6x: 38.4 - 112mm	42 - 105mm
Lens Construction	17 elements in 12 groups, including 3 LD, 3 glass-molded aspherical, 1 hybrid aspherical and 2 XR (Extra Refractive Index) elements	14 elements in 11 groups
Image Circle	Image Circle	35mm
Focal Length (mm)	24.00 - 70.00	28.00 - 70.00
Brand	Tamron	Pentax
Name	Tamron SP 24-70mm ƒ/2.8 Di VC USD (Model A007)	Pentax SMC P-FA 28-70mm f/2.8
Weight (g)	825	800
Diameter (mm)	88.2	84
Length (mm)	116.9	104
Diaphragm Blades	9	-
Magnification Ratio (x)	0.2	0.25
Diaphragm Blades Type	rounded	-
Closest Focus (m)	0.38	0.43