The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F4-5.6 EX DC HSM and the Tamron 11-18mm f4.5-5.6 II LD 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 10-20mm F4-5.6 EX DC HSM is the longer of the two lenses at 81mm. The Tamron 11-18mm f4.5-5.6 II LD with a length of 79mm, is 2mm shorter. Besides being longer, the Sigma 10-20mm F4-5.6 EX DC HSM also has a larger diameter of 84mm compared to the Tamron 11-18mm f4.5-5.6 II LD's 83mm 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 11-18mm f4.5-5.6 II LD weighs 355g, 24% (115g) lighter than the Sigma 10-20mm F4-5.6 EX DC HSM's weight of 470g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Nikon F (DX) Mount for size comparison purposes.
Ultra-Wideangle Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Tamron 11-18mm f4.5-5.6 II LD have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Tamron 11-18mm f4.5-5.6 II LD has the same Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (DX) lenses are Nikon D3500, Nikon D7500 and Nikon D5600.
Sigma 10-20mm F4-5.6 EX DC HSM is also available in Canon EF , Four Thirds, Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
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.
On the other hand, the Tamron 11-18mm f4.5-5.6 II LD has a focal range of 11-18mm and 1.6X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 16.5-27mm when used on a APS-C / DX format camera.