The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24-70mm F2.8 II and the Tamron 28-75mm F2.8 Di III 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 24-70mm F2.8 II is the longer of the two lenses at 122mm. The Tamron 28-75mm F2.8 Di III with a length of 118mm, is 4mm shorter. Besides being longer, the Sigma 24-70mm F2.8 II also has a larger diameter of 88mm compared to the Tamron 28-75mm F2.8 Di III's 76mm diameter.
Below you can find a scaled side-by-side image of Sigma 24-70mm F2.8 II and Tamron 28-75mm F2.8 Di III to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 24-70mm F2.8 II and the Tamron 28-75mm F2.8 Di III 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. Tamron 28-75mm F2.8 Di III weighs 540g, 26% (195g) lighter than the Sigma 24-70mm F2.8 II's weight of 735g.
Filter Threads
The Sigma 24-70mm F2.8 II has a filter size of 82mm whereas the Tamron 28-75mm F2.8 Di III has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Sigma 24-70mm F2.8 II:
And these are the 67mm filters that we recommend for the Tamron 28-75mm F2.8 Di III:
Lens Mounts
The Sigma 24-70mm F2.8 II has the Sony E lens mount whereas the Tamron 28-75mm F2.8 Di III has the Nikon Z lens mount . Some of the latest released cameras that are compatible with these mounts are Sony FX5 , Sony A7R VI and Sony A7 V for the Sony E Mount and Nikon ZR , Nikon Z5 II and RED Komodo-X 6K Z for the Nikon Z Mount.
Sigma 24-70mm F2.8 II is also available in the Leica L mount.
Tamron 28-75mm F2.8 Di III is also available in Sony E and Sony E mounts.
Focal Range
Sigma 24-70mm F2.8 II has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36 - 105mm .
On the other hand, the Tamron 28-75mm F2.8 Di III has a focal range of 28-75mm and 2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 112.5mm .