The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 16-35mm F2.8 GM and the Tamron 17-28mm F2.8 Di III 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 FE 16-35mm F2.8 GM is the longer of the two lenses at 122mm. The Tamron 17-28mm F2.8 Di III with a length of 99mm, is 23mm shorter. Besides being longer, the Sony FE 16-35mm F2.8 GM also has a larger diameter of 89mm compared to the Tamron 17-28mm F2.8 Di III's 73mm diameter.
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Below you can find a scaled side-by-side image of Sony FE 16-35mm F2.8 GM and Tamron 17-28mm F2.8 Di III to get a better idea of how their sizes compare in real life.
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 17-28mm F2.8 Di III weighs 420g, 38% (260g) lighter than the Sony FE 16-35mm F2.8 GM's weight of 680g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Sony E Mount for size comparison purposes.
Ultra-Wideangle Lenses in Sony E Mount for Size Comparison
Filter Threads
The Sony FE 16-35mm F2.8 GM has a filter size of 82mm whereas the Tamron 17-28mm F2.8 Di III 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 82mm filters that we recommend you to consider for the Sony FE 16-35mm F2.8 GM:
And these are the 67mm filters that we recommend for the Tamron 17-28mm F2.8 Di III:
Lens Mounts
Both the Sony FE 16-35mm F2.8 GM and the Tamron 17-28mm F2.8 Di III has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A9 III, Sony A7C Mark II and Sony A7CR.
Focal Range
Sony FE 16-35mm F2.8 GM has a focal range of 16-35mm and
2.2X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
24 - 52.5mm.
On the other hand, the Tamron 17-28mm F2.8 Di III has a focal range of 17-28mm and 1.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 25.5 - 42mm.