The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 20mm F2.8 Di III OSD M1:2 and the 7artisans 12mm F2.8 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. 7artisans 12mm F2.8 is the longer of the two lenses at 66mm. The Tamron 20mm F2.8 Di III OSD M1:2 with a length of 64mm, is 2mm shorter. On the other hand, the Tamron 20mm F2.8 Di III OSD M1:2 has a larger diameter of 73mm compared to the 7artisans 12mm F2.8's 63mm 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, which means it is 75g (25%) lighter than the 7artisans 12mm F2.8 which has a weight of 295g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Sony E Mount for size comparison purposes.
Ultra-Wideangle Lenses in Sony E Mount for Size Comparison
Filter Threads
The Tamron 20mm F2.8 Di III OSD M1:2 has a filter size of 67mm whereas the 7artisans 12mm F2.8 has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 20mm F2.8 Di III OSD M1:2:
And these are the 46mm filters that we recommend for the 7artisans 12mm F2.8:
Lens Mounts
Both the Tamron 20mm F2.8 Di III OSD M1:2 and the 7artisans 12mm F2.8 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.
7artisans 12mm F2.8 is also available in Canon EF-M and Fujifilm X mounts.
Focal Range
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.
On the other hand, the 7artisans 12mm F2.8 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.
