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 an important deciding factor 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 as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer 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 Canon EF Mount for size comparison purposes.
SuperZoom Lenses in Canon EF Mount for Size Comparison
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 Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Tamron 18-200mm F3.5-6.3 Di II VC is also available in Nikon F (DX) and Sony Alpha mounts.
Tamron 28-300mm f3.5-6.3 VC PZD is also available in Nikon F (FX) and Sony Alpha 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 28.8-320mm when used on a APS-C / DX format camera. 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 1.6x crop, it provides a 35mm (FF) equivalent of 44.8 - 480mm.