The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-28mm F2.8 Di III and the Sigma 10-20mm F4-5.6 EX DC HSM 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 17-28mm F2.8 Di III is the longer of the two lenses at 99mm. The Sigma 10-20mm F4-5.6 EX DC HSM with a length of 81mm, is 18mm shorter. On the other hand, the Sigma 10-20mm F4-5.6 EX DC HSM has a larger diameter of 84mm compared to the Tamron 17-28mm F2.8 Di III's 73mm 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 17-28mm F2.8 Di III weighs 420g, which means it is 50g (10%) lighter than the Sigma 10-20mm F4-5.6 EX DC HSM which has a weight of 470g.
Filter Threads
The Tamron 17-28mm F2.8 Di III has a filter size of 67mm whereas the Sigma 10-20mm F4-5.6 EX DC HSM has a 77mm 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 17-28mm F2.8 Di III:
And these are the 77mm filters that we recommend for the Sigma 10-20mm F4-5.6 EX DC HSM:
Lens Mounts
The Tamron 17-28mm F2.8 Di III has the Sony E lens mount whereas the Sigma 10-20mm F4-5.6 EX DC HSM has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 10-20mm F4-5.6 EX DC HSM is also available in Canon EF , Four Thirds, Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Tamron 17-28mm F2.8 Di III has a focal range of 17-28mm and
1.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
25.5 - 42mm.
On the other hand, the Sigma 10-20mm F4-5.6 EX DC HSM has a focal range of 10-20mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-30mm when used on a APS-C / DX format camera.
