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 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. Sigma 17-70mm F2.8-4 DC OS HSM is the longer of the two lenses at 89mm. The Tamron 17-35mm f2.8-4 LD with a length of 87mm, is 2mm shorter. On the other hand, the Tamron 17-35mm f2.8-4 LD has a larger diameter of 83mm 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. Tamron 17-35mm f2.8-4 LD weighs 440g, which means it is 80g (15%) lighter than the Sigma 17-70mm F2.8-4 DC OS HSM which has a weight of 520g.
Filter Threads
The Tamron 17-35mm f2.8-4 LD has a filter size of 77mm whereas the Sigma 17-70mm F2.8-4 DC OS HSM has a 72mm 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 LD:
And these are the 72mm filters that we recommend for the Sigma 17-70mm F2.8-4 DC OS HSM:
Lens Mounts
The Tamron 17-35mm f2.8-4 LD has the Canon EF lens mount whereas the Sigma 17-70mm F2.8-4 DC OS HSM has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Tamron 17-35mm f2.8-4 LD is also available in the Nikon F (FX) 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 17-35mm f2.8-4 LD 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 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.
