The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 100-400mm F4.5-5.6 and the Samyang 300mm f6.3 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. Sony FE 100-400mm F4.5-5.6 is the longer of the two lenses at 205mm. The Samyang 300mm f6.3 with a length of 74mm, is 131mm shorter. Besides being longer, the Sony FE 100-400mm F4.5-5.6 also has a larger diameter of 94mm compared to the Samyang 300mm f6.3's 65mm diameter.
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. Samyang 300mm f6.3 weighs 318g, 77% (1077g) lighter than the Sony FE 100-400mm F4.5-5.6's weight of 1395g.
Lens Mounts
Both the Sony FE 100-400mm F4.5-5.6 and the Samyang 300mm f6.3 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.
Samyang 300mm f6.3 is also available in Canon EF-M , Fujifilm X and Micro Four Thirds mounts.
Focal Range
Sony FE 100-400mm F4.5-5.6 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.
On the other hand, the Samyang 300mm f6.3 is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of 450mm when used on a APS-C / DX format camera.
