The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 25-200mm f2.8-5.6 Di and the Tamron 18-200mm f3.5-6.3 III VC 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 25-200mm f2.8-5.6 Di is the longer of the two lenses at 122mm. The Tamron 18-200mm f3.5-6.3 III VC with a length of 97mm, is 25mm shorter. Besides being longer, the Tamron 25-200mm f2.8-5.6 Di also has a larger diameter of 76mm compared to the Tamron 18-200mm f3.5-6.3 III VC's 68mm 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 III VC weighs 460g, 19% (115g) lighter than the Tamron 25-200mm f2.8-5.6 Di's weight of 575g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Sony E Mount for size comparison purposes.
Superzoom Lenses in Sony E Mount for Size Comparison
Filter Threads
The Tamron 25-200mm f2.8-5.6 Di has a filter size of 67mm whereas the Tamron 18-200mm f3.5-6.3 III VC has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 25-200mm f2.8-5.6 Di:
And these are the 62mm filters that we recommend for the Tamron 18-200mm f3.5-6.3 III VC:
Lens Mounts
Both the Tamron 25-200mm f2.8-5.6 Di and the Tamron 18-200mm f3.5-6.3 III VC has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX5, Sony A7R VI and Sony A7 V.
Focal Range
Tamron 25-200mm f2.8-5.6 Di has a focal range of 25-200mm and
8.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
37.5 - 300mm.
On the other hand, the Tamron 18-200mm f3.5-6.3 III 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.
