The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-50mm f2.8 XR II VC LD and the Sigma 17-50mm F2.8 EX DC OS HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Tamron 17-50mm f2.8 XR II VC LD is the longer of the two lenses at 95mm. The Sigma 17-50mm F2.8 EX DC OS HSM with a length of 92mm, is 3mm shorter. On the other hand, the Sigma 17-50mm F2.8 EX DC OS HSM has a larger diameter of 84mm compared to the Tamron 17-50mm f2.8 XR II VC LD's 80mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 17-50mm F2.8 EX DC OS HSM weighs 565g, 0% (5g) lighter than the Tamron 17-50mm f2.8 XR II VC LD's weight of 570g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Canon EF Mount for size comparison purposes.
Standard Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Tamron 17-50mm f2.8 XR II VC LD and the Sigma 17-50mm F2.8 EX DC OS HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Tamron 17-50mm f2.8 XR II VC LD is also available in Nikon F (DX) mount.
Sigma 17-50mm F2.8 EX DC OS HSM is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Both lenses have the same focal range of 17-50mm and the fastest aperture of F2.8.