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 17-70mm F2.8-4 DC OS 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 17-50mm f2.8 XR II VC LD is the longer of the two lenses at 95mm. The Sigma 17-70mm F2.8-4 DC OS HSM with a length of 89mm, is 6mm shorter. Besides being longer, the Tamron 17-50mm f2.8 XR II VC LD also has a larger diameter of 80mm compared to the Sigma 17-70mm F2.8-4 DC OS HSM's 79mm 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 17-70mm F2.8-4 DC OS HSM weighs 520g, 8% (50g) 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 Nikon F (DX) Mount for size comparison purposes.
Standard Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
Both the Tamron 17-50mm f2.8 XR II VC LD and the Sigma 17-70mm F2.8-4 DC OS HSM have the same Filter thread size of 72mm.
Below are links to the 72mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Tamron 17-50mm f2.8 XR II VC LD and the Sigma 17-70mm F2.8-4 DC OS HSM 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.
Tamron 17-50mm f2.8 XR II VC LD is also available in the Canon EF mount.
Sigma 17-70mm F2.8-4 DC OS HSM is also available in Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Tamron 17-50mm f2.8 XR II VC LD has a focal range of 17-50mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-75mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 17-70mm F2.8-4 DC OS HSM has a focal range of 17-70mm and 4.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 25.5-105mm when used on a APS-C / DX format camera.
