Comparison of Pentax SMC P-FA 135mm f/2.8 IF and Tamron AF 28-105mm f/4-5.6 IF

Attribute	Pentax SMC P-FA 135mm f/2.8 IF ×	Tamron AF 28-105mm f/4-5.6 IF ×
Weight (g)	374	305
Type	Telephoto Prime	Standard Zoom
Brand	Pentax	Tamron
Name	Pentax SMC P-FA 135mm f/2.8 IF	Tamron AF 28-105mm f/4-5.6 IF
Diameter (mm)	64	71
Image Circle	35mm	35mm
Lens Construction	8 elements in 7 groups	15 elements in 12 groups
Notes	-	Available AF Mounts: Canon, Minolta, Nikon; Included Accessories: Lens Hood
Closest Focus (m)	0.7	0.5
Focus Details	Internal	Internal
Filter Size (mm)	52	62
Aperture (f)	2.80 - 22.00	4.00 - 22.00
Diagonal Angle of View (degree)	18.00	-
Diaphragm Blades	-	6
APS Equivalent	202.5mm	1.5x: 42-157.5mm; 1.6x: 44.8-168mm
Magnification Ratio (x)	-	0.18
Focal Length (mm)	135.00	28.00 - 105.00
Zoom System	-	Rotary
Length (mm)	79	73