The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-18mm F2.8 DC DN C and the Tamron 20mm F2.8 Di III OSD M1:2 for their suitability to various photography scenarios:
Size and Weight Comparison
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, 13% (35g) lighter than the Sigma 10-18mm F2.8 DC DN C's weight of 255g.
Filter Threads
Both the Sigma 10-18mm F2.8 DC DN C 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 Sigma 10-18mm F2.8 DC DN C 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 ZV-E10 II, Sony A6700 and Sony FX30.
Sigma 10-18mm F2.8 DC DN C is also available in the Leica L , Fujifilm X and Canon RF mounts.
Focal Range
Sigma 10-18mm F2.8 DC DN C has a focal range of 10-18mm and
1.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-27mm when used on a APS-C / DX format camera.
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.
