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 Sony DT 18-135mm F3.5-5.6 SAM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sony DT 18-135mm F3.5-5.6 SAM is the longer of the two lenses at 86mm. The Tamron AF 18-200mm f3.5-6.3 XR II LD with a length of 84mm, is 2mm shorter. Besides being longer, the Sony DT 18-135mm F3.5-5.6 SAM also has a larger diameter of 76mm compared to the Tamron AF 18-200mm f3.5-6.3 XR II LD's 74mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods.
Below you can find the dimension and weight table of the SuperZoom Lenses in Sony Alpha Mount for size comparison purposes.
Superzoom Lenses in Sony Alpha Mount for Size Comparison
Filter Threads
Both the Tamron AF 18-200mm f3.5-6.3 XR II LD and the Sony DT 18-135mm F3.5-5.6 SAM have the same Filter thread size of 62mm.
Below are links to the 62mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Tamron AF 18-200mm f3.5-6.3 XR II LD and the Sony DT 18-135mm F3.5-5.6 SAM has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Tamron AF 18-200mm f3.5-6.3 XR II LD is also available in Canon EF , Nikon F (DX) and Pentax KAF mounts.
Focal Range
Tamron AF 18-200mm f3.5-6.3 XR II LD has a focal range of 18-200mm and
11.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-300mm when used on a APS-C / DX format camera.
On the other hand, the Sony DT 18-135mm F3.5-5.6 SAM has a focal range of 18-135mm and 7.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-202.5mm when used on a APS-C / DX format camera.