The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-35mm F2.8-4 Di OSD and the Sigma 10-20mm F3.5 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 17-35mm F2.8-4 Di OSD is the longer of the two lenses at 93mm. The Sigma 10-20mm F3.5 EX DC HSM with a length of 88mm, is 5mm shorter. On the other hand, the Sigma 10-20mm F3.5 EX DC HSM has a larger diameter of 87mm compared to the Tamron 17-35mm F2.8-4 Di OSD's 84mm 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 17-35mm F2.8-4 Di OSD weighs 460g, which means it is 60g (11%) lighter than the Sigma 10-20mm F3.5 EX DC HSM which has a weight of 520g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon EF Mount for Size Comparison
Filter Threads
The Tamron 17-35mm F2.8-4 Di OSD has a filter size of 77mm whereas the Sigma 10-20mm F3.5 EX DC HSM has a 82mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Tamron 17-35mm F2.8-4 Di OSD:
And these are the 82mm filters that we recommend for the Sigma 10-20mm F3.5 EX DC HSM:
Lens Mounts
Both the Tamron 17-35mm F2.8-4 Di OSD and the Sigma 10-20mm F3.5 EX DC HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron 17-35mm F2.8-4 Di OSD is also available in Nikon F (FX) mount.
Sigma 10-20mm F3.5 EX DC HSM is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Tamron 17-35mm F2.8-4 Di OSD has a focal range of 17-35mm and
2.1X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
27.2 - 56mm.
On the other hand, the Sigma 10-20mm F3.5 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 16-32mm when used on a APS-C / DX format camera.