The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 18-200mm f3.5-6.3 XR II LD and the Sigma 18-200mm F3.5-6.3 DC for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Tamron AF 18-200mm f3.5-6.3 XR II LD is the longer of the two lenses at 84mm. The Sigma 18-200mm F3.5-6.3 DC with a length of 78mm is 6mm shorter. Besides being longer, the Tamron AF 18-200mm f3.5-6.3 XR II LD also has a larger diameter of 74mm compared to Sigma 18-200mm F3.5-6.3 DC's 70mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Tamron AF 18-200mm f3.5-6.3 XR II LD weighs 398g, which means it is 7g (1%) lighter than the Sigma 18-200mm F3.5-6.3 DC which has a weight of 405g.
Below you can find the dimension and weight table of the 'SuperZoom Lenses in Pentax KAF Mount for size comparison purposes.
SuperZoom Lenses in Pentax KAF Mount for Size Comparison
Both Tamron AF 18-200mm f3.5-6.3 XR II LD and Sigma 18-200mm F3.5-6.3 DC has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax KF, Pentax K-3 III and Pentax KP.
Tamron AF 18-200mm f3.5-6.3 XR II LD is also available in Canon EF , Nikon F (DX) and Sony Alpha mounts.
Sigma 18-200mm F3.5-6.3 DC is also available in Canon EF , Nikon F (DX), Sony Alpha and Sigma SA mounts.
Both lenses have the same focal range of 18-200mm and the fastest aperture of F3.5 - F6.3.