The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 100-400mm F5-6.3 OS and the Sony FE 100-400mm F4.5-5.6 GM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sony FE 100-400mm F4.5-5.6 GM is the longer of the two lenses at 205mm. The Sigma 100-400mm F5-6.3 OS with a length of 197mm, is 8mm shorter. Besides being longer, the Sony FE 100-400mm F4.5-5.6 GM also has a larger diameter of 94mm compared to the Sigma 100-400mm F5-6.3 OS's 86mm diameter.
Below you can find a scaled side-by-side image of Sigma 100-400mm F5-6.3 OS and Sony FE 100-400mm F4.5-5.6 GM to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 100-400mm F5-6.3 OS and the Sony FE 100-400mm F4.5-5.6 GM Size and Weight The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 100-400mm F5-6.3 OS weighs 1135g, which means it is 260g (18%) lighter than the Sony FE 100-400mm F4.5-5.6 GM which has a weight of 1395g.
Below you can find the dimension and weight table of the Telephoto Zoom Lenses in Sony E Mount for size comparison purposes.
Telephoto Zoom Lenses in Sony E Mount for Size Comparison
Lens Mounts
Both the Sigma 100-400mm F5-6.3 OS and the Sony FE 100-400mm F4.5-5.6 GM has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E1, Sony A7R V and Sony FX30.
Sigma 100-400mm F5-6.3 OS is also available in Leica L mount.
Focal Range
Both lenses have the same focal range of 100-400mm but while Sigma 100-400mm F5-6.3 OS has the fastest aperture of F5-6.3, the Sony FE 100-400mm F4.5-5.6 GM's widest aperture value is F4.5-5.6.