Comparison of Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA and Sigma 28-135mm f/3.8-5.6 Aspherical IF Macro

Attribute	Sigma 28-135mm f/3.8-5.6 Aspherical IF Macro ×	Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA ×
Notes	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax	Weather-resistant. Included Accessories: Lens Hood
Magnification Ratio (x)	0.5	0.24
Filter Size (mm)	62	62
Length (mm)	75	76
Closest Focus (m)	0.24	0.4
Diagonal Angle of View (degree)	18.20 - 75.40	11.90 - 76.00
Focus Details	Internal	Internal with "Quick Shift" AF/MF mechanism and DC motor
Focal Length (mm)	28.00 - 135.00	18.00 - 135.00
APS Equivalent	1.5x: 42 - 202.5mm; 1.6x: 44.8 - 216mm	27.5 - 207mm
Brand	Sigma	Pentax
Image Circle	35mm	APS-C
Name	Sigma 28-135mm f/3.8-5.6 Aspherical IF Macro	Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA
Weight (g)	410	405
Type	Standard Zoom	Standard Zoom
Aperture (f)	3.80 - 22.00	3.50 - 40.00
Diaphragm Blades	7	7
Diaphragm Blades Type	-	rounded
Lens Construction	13 elements in 12 groups, including 1 aspherical element	13 elements in 11 groups, including 1 ED ands 2 aspherical elements
Zoom System	Rotary	Rotary
Diameter (mm)	75	73