The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 11-20mm F2.8 Di III-A and the Sony E 10-18mm F4 OSS for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Tamron 11-20mm F2.8 Di III-A is the longer of the two lenses at 86mm. The Sony E 10-18mm F4 OSS with a length of 64mm is 22mm shorter. Besides being longer, the Tamron 11-20mm F2.8 Di III-A also has a larger diameter of 73mm compared to Sony E 10-18mm F4 OSS's 70mm diameter.
Below you can find the scaled side by side image of Tamron 11-20mm F2.8 Di III-A and Sony E 10-18mm F4 OSS to get a better idea of how their size compare in real life.
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. Sony E 10-18mm F4 OSS weighs 225g, 32% (110g) lighter than the Tamron 11-20mm F2.8 Di III-A's weight of 335g.
Below you can find the dimension and weight table of the 'Wideangle Zoom Lenses in Sony E Mount for size comparison purposes.
Wideangle Zoom Lenses in Sony E Mount for Size Comparison
Both Tamron 11-20mm F2.8 Di III-A and Sony E 10-18mm F4 OSS has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A7R V, Sony FX30 and Sony A7 IV.
Tamron 11-20mm F2.8 Di III-A has a focal range of 11-20mm and 1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 16.5 - 30mm.
Sony E 10-18mm F4 OSS has a focal range of 10-18mm and 1.8X zoom ratio which has a 35mm equivalent focal range of 15-27mm when used on a APS-C / DX format camera.