The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina Opera 16-28mm F2.8 FF 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. Tokina Opera 16-28mm F2.8 FF is the longer of the two lenses at 134mm. The Sigma 10-20mm F4-5.6 EX DC HSM with a length of 81mm, is 53mm shorter. Besides being longer, the Tokina Opera 16-28mm F2.8 FF also has a larger diameter of 89mm compared to the Sigma 10-20mm F4-5.6 EX DC HSM'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. Sigma 10-20mm F4-5.6 EX DC HSM weighs 470g, 50% (470g) lighter than the Tokina Opera 16-28mm F2.8 FF's weight of 940g.
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
Lens Mounts
Both the Tokina Opera 16-28mm F2.8 FF and the Sigma 10-20mm F4-5.6 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.
Tokina Opera 16-28mm F2.8 FF is also available in Nikon F (FX) mount.
Sigma 10-20mm F4-5.6 EX DC HSM is also available in Four Thirds , Pentax KAF, Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Tokina Opera 16-28mm F2.8 FF has a focal range of 16-28mm and
1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
25.6 - 44.8mm.
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 16-32mm when used on a APS-C / DX format camera.