The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 28-70mm F2.8 DG DN and the Tamron 17-70 F2.8 Di III-A VC 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 17-70 F2.8 Di III-A VC is the longer of the two lenses at 119mm. The Sigma 28-70mm F2.8 DG DN with a length of 102mm, is 17mm shorter. Besides being longer, the Tamron 17-70 F2.8 Di III-A VC also has a larger diameter of 75mm compared to the Sigma 28-70mm F2.8 DG DN's 72mm diameter.
Below you can find a scaled side-by-side image of Sigma 28-70mm F2.8 DG DN and Tamron 17-70 F2.8 Di III-A VC to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 28-70mm F2.8 DG DN and the Tamron 17-70 F2.8 Di III-A VC Size and Weight 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 28-70mm F2.8 DG DN weighs 470g, which means it is 55g (10%) lighter than the Tamron 17-70 F2.8 Di III-A VC which has a weight of 525g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Sony E Mount for size comparison purposes.
Standard Sony E Mount
Filter Threads
Both the Sigma 28-70mm F2.8 DG DN and the Tamron 17-70 F2.8 Di III-A VC have the same Filter thread size of 67mm .
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sigma 28-70mm F2.8 DG DN and the Tamron 17-70 F2.8 Di III-A VC has the same Sony E lens mount . Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX5 , Sony A7R VI and Sony A7 V .
Fujifilm X mount.
Focal Range
Sigma 28-70mm F2.8 DG DN has a focal range of 28-70mm and
2.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
42 - 105mm .
On the other hand, the Tamron 17-70 F2.8 Di III-A VC 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.
