The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 50-400mm F4.5-6.3 VC and the Sigma 100-400mm F5-6.3 OS 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 100-400mm F5-6.3 OS is the longer of the two lenses at 197mm. The Tamron 50-400mm F4.5-6.3 VC with a length of 183mm, is 14mm shorter. On the other hand, the Tamron 50-400mm F4.5-6.3 VC has a larger diameter of 89mm compared to the Sigma 100-400mm F5-6.3 OS's 86mm diameter.
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Below you can find a scaled side-by-side image of Tamron 50-400mm F4.5-6.3 VC and Sigma 100-400mm F5-6.3 OS 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. Sigma 100-400mm F5-6.3 OS weighs 1135g, 1% (20g) lighter than the Tamron 50-400mm F4.5-6.3 VC's weight of 1155g.
Below you can find the dimension and weight table of the Telephoto Zoom Lenses in Sony E Mount for size comparison purposes.
Super Telephoto Lenses in Sony E Mount for Size Comparison
Filter Threads
Both the Tamron 50-400mm F4.5-6.3 VC and the Sigma 100-400mm F5-6.3 OS 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 Tamron 50-400mm F4.5-6.3 VC and the Sigma 100-400mm F5-6.3 OS 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.
Sigma 100-400mm F5-6.3 OS is also available in Leica L and Fujifilm X mounts.
Focal Range
Tamron 50-400mm F4.5-6.3 VC has a focal range of 50-400mm and
8.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75 - 600mm.
On the other hand, the Sigma 100-400mm F5-6.3 OS has a focal range of 100-400mm and 4.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 150 - 600mm.