The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 24-70mm f2.8 AF 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. Samyang 24-70mm f2.8 AF is the longer of the two lenses at 129mm. The Tamron 17-70 F2.8 Di III-A VC with a length of 119mm, is 10mm shorter. Besides being longer, the Samyang 24-70mm f2.8 AF also has a larger diameter of 88mm compared to the Tamron 17-70 F2.8 Di III-A VC's 75mm diameter.
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Below you can find a scaled side-by-side image of Samyang 24-70mm f2.8 AF and Tamron 17-70 F2.8 Di III-A VC to get a better idea of how their sizes compare in real life.
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 17-70 F2.8 Di III-A VC weighs 525g, 48% (502g) lighter than the Samyang 24-70mm f2.8 AF's weight of 1027g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Sony E Mount for size comparison purposes.
Standard Lenses in Sony E Mount for Size Comparison
Filter Threads
The Samyang 24-70mm f2.8 AF has a filter size of 82mm whereas the Tamron 17-70 F2.8 Di III-A VC 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 Samyang 24-70mm f2.8 AF:
And these are the 67mm filters that we recommend for the Tamron 17-70 F2.8 Di III-A VC:
Lens Mounts
Both the Samyang 24-70mm f2.8 AF 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 A9 III, Sony A7C Mark II and Sony A7CR.
Tamron 17-70 F2.8 Di III-A VC is also available in Fujifilm X mount.
Focal Range
Samyang 24-70mm f2.8 AF 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 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.