Comparison of Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA and Sigma 18-125mm f/3.5-5.6 DC

Attribute	Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA ×	Sigma 18-125mm f/3.5-5.6 DC ×
Notes	Weather-resistant. Included Accessories: Lens Hood	Available AF Mounts: Sigma, Canon, Nikon, Minolta, Pentax, Four-Thirds
Magnification Ratio (x)	0.24	0.19
Filter Size (mm)	62	62
Length (mm)	76	70
Closest Focus (m)	0.4	0.5
Diagonal Angle of View (degree)	11.90 - 76.00	11.40 - 69.30
Focus Details	Internal with "Quick Shift" AF/MF mechanism and DC motor	Inner focusing system
Focal Length (mm)	18.00 - 135.00	18.00 - 125.00
APS Equivalent	27.5 - 207mm	1.5x: 27 - 187.5mm; 1.6x: 28.8 - 200mm
Brand	Pentax	Sigma
Image Circle	APS-C	Image Circle
Name	Pentax 18-135mm ƒ/3.5-5.6 ED AL [IF] DC WR SMC DA	Sigma 18-125mm f/3.5-5.6 DC
Weight (g)	405	385
Type	Standard Zoom	Standard Zoom
Aperture (f)	3.50 - 40.00	3.50 - 22.00
Diaphragm Blades	7	7
Diaphragm Blades Type	rounded	-
Lens Construction	13 elements in 11 groups, including 1 ED ands 2 aspherical elements	15 elements in 14 groups, including two aspherical elements and one Special Low Dispersion (SLD) lens
Zoom System	Rotary	Rotary
Diameter (mm)	73	77.7