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 A and the Tamron 17-70 F2.8 Di III-A 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 17-70 F2.8 Di III-A VC is the longer of the two lenses at 119mm. The Tamron 11-20mm F2.8 A with a length of 86mm, is 33mm shorter. Besides being longer, the Tamron 17-70 F2.8 Di III-A VC also has a larger diameter of 75mm compared to the Tamron 11-20mm F2.8 A's 73mm diameter.
Below you can find a scaled side-by-side image of Tamron 11-20mm F2.8 A and Tamron 17-70 F2.8 Di III-A VC to get a better idea of how their sizes compare in real life.
Comparison image of the Tamron 11-20mm F2.8 A and the Tamron 17-70 F2.8 Di III-A VC Size and Weight 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 11-20mm F2.8 A weighs 335g, which means it is 190g (36%) lighter than the Tamron 17-70 F2.8 Di III-A VC which has a weight of 525g.
Filter Threads
Both the Tamron 11-20mm F2.8 A and the Tamron 17-70 F2.8 Di III-A VC 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 Tamron 11-20mm F2.8 A and the Tamron 17-70 F2.8 Di III-A VC 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 .
Tamron 17-70 F2.8 Di III-A VC is also available in Fujifilm X mount.
Focal Range
Tamron 11-20mm F2.8 A has a focal range of 11-20mm and
1.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16.5-30mm when used on a APS-C / DX format camera.
On the other hand, the Tamron 17-70 F2.8 Di III-A VC has a focal range of 17-70mm and 4.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 25.5-105mm when used on a APS-C / DX format camera.