The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F2 DG DN C and the Tamron 24mm F2.8 Di III OSD M1:2 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. Sigma 20mm F2 DG DN C is the longer of the two lenses at 72mm. The Tamron 24mm F2.8 Di III OSD M1:2 with a length of 64mm, is 8mm shorter. On the other hand, the Tamron 24mm F2.8 Di III OSD M1:2 has a larger diameter of 73mm compared to the Sigma 20mm F2 DG DN C's 70mm 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 24mm F2.8 Di III OSD M1:2 weighs 215g, 41% (155g) lighter than the Sigma 20mm F2 DG DN C's weight of 370g.
Filter Threads
The Sigma 20mm F2 DG DN C has a filter size of 62mm whereas the Tamron 24mm F2.8 Di III OSD M1:2 has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Sigma 20mm F2 DG DN C:
And these are the 67mm filters that we recommend for the Tamron 24mm F2.8 Di III OSD M1:2:
Lens Mounts
Both the Sigma 20mm F2 DG DN C and the Tamron 24mm 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 A9 III, Sony A7C Mark II and Sony A7CR.
Sigma 20mm F2 DG DN C is also available in Leica L mount.
Focal Range
Sigma 20mm F2 DG DN C 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 Tamron 24mm F2.8 Di III OSD M1:2 is a prime lens with fixed focal lenght of 24mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 36mm.