The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 16-25mm F2.8 and the Tamron 20mm F2.8 Di III OSD M1:2 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 16-25mm F2.8 is the longer of the two lenses at 91mm. The Tamron 20mm F2.8 Di III OSD M1:2 with a length of 64mm, is 27mm shorter. Besides being longer, the Sony FE 16-25mm F2.8 also has a larger diameter of 75mm compared to the Tamron 20mm F2.8 Di III OSD M1:2's 73mm 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 20mm F2.8 Di III OSD M1:2 weighs 220g, 46% (189g) lighter than the Sony FE 16-25mm F2.8's weight of 409g.
Filter Threads
Both the Sony FE 16-25mm F2.8 and the Tamron 20mm F2.8 Di III OSD M1:2 have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sony FE 16-25mm F2.8 and the Tamron 20mm F2.8 Di III OSD M1:2 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
Sony FE 16-25mm F2.8 has a focal range of 16-25mm and
1.6X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
24 - 37.5mm.
On the other hand, the Tamron 20mm F2.8 Di III OSD M1:2 is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 30mm.