The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 28-200mm f3.8-5.6 XR and the Tamron 18-270mm f3.5-6.3 II PZD 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 18-270mm f3.5-6.3 II PZD is the longer of the two lenses at 88mm. The Tamron AF 28-200mm f3.8-5.6 XR with a length of 75mm is 13mm shorter. Besides being longer, the Tamron 18-270mm f3.5-6.3 II PZD also has a larger diameter of 74mm compared to Tamron AF 28-200mm f3.8-5.6 XR's 71mm 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 28-200mm f3.8-5.6 XR weighs 354g, which means it is 96g (21%) lighter than the Tamron 18-270mm f3.5-6.3 II PZD which has a weight of 450g.
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
Lens Mounts
Both Tamron AF 28-200mm f3.8-5.6 XR and Tamron 18-270mm f3.5-6.3 II PZD has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Tamron AF 28-200mm f3.8-5.6 XR is also available in Canon EF , Nikon F (FX) and Pentax KAF mounts.
Focal Range
Tamron AF 28-200mm f3.8-5.6 XR has a focal range of 28-200mm and 7.1X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 42 - 300mm.
Tamron 18-270mm f3.5-6.3 II PZD has a focal range of 18-270mm and 15.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-405mm when used on a APS-C / DX format camera.