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 X and the Carl Zeiss Touit 2.8/12 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. Carl Zeiss Touit 2.8/12 weighs 270g, 19% (65g) lighter than the Tamron 11-20mm F2.8 X's weight of 335g.
Filter Threads
Both the Tamron 11-20mm F2.8 X and the Carl Zeiss Touit 2.8/12 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 X and the Carl Zeiss Touit 2.8/12 has the same Fujifilm X lens mount. Some of the latest released cameras that are compatible with the Fujifilm X lenses are Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5.
Carl Zeiss Touit 2.8/12 is also available in Sony E mount.
Focal Range
Tamron 11-20mm F2.8 X 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 Carl Zeiss Touit 2.8/12 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of 18mm when used on a APS-C / DX format camera.