The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 18-200mm F3.5-6.3 Di II VC and the Tamron 28-300mm f3.5-6.3 VC PZD 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. Tamron 18-200mm F3.5-6.3 Di II VC is the longer of the two lenses at 97mm. The Tamron 28-300mm f3.5-6.3 VC PZD with a length of 96mm, is 1mm shorter. Besides being longer, the Tamron 18-200mm F3.5-6.3 Di II VC also has a larger diameter of 75mm compared to the Tamron 28-300mm f3.5-6.3 VC PZD'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. Tamron 18-200mm F3.5-6.3 Di II VC weighs 400g, which means it is 140g (25%) lighter than the Tamron 28-300mm f3.5-6.3 VC PZD which has a weight of 540g.
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
The Tamron 18-200mm F3.5-6.3 Di II VC has a filter size of 62mm whereas the Tamron 28-300mm f3.5-6.3 VC PZD has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Tamron 18-200mm F3.5-6.3 Di II VC:
And these are the 67mm filters that we recommend for the Tamron 28-300mm f3.5-6.3 VC PZD:
Lens Mounts
Both the Tamron 18-200mm F3.5-6.3 Di II VC and the Tamron 28-300mm f3.5-6.3 VC PZD 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 18-200mm F3.5-6.3 Di II VC is also available in Canon EF and Nikon F (DX) mounts.
Tamron 28-300mm f3.5-6.3 VC PZD is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Tamron 18-200mm F3.5-6.3 Di II VC 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 Tamron 28-300mm f3.5-6.3 VC PZD has a focal range of 28-300mm and 10.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 450mm.