The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 70-200mm F4 G OSS II and the Rokinon 85mm F1.8 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 70-200mm F4 G OSS II is the longer of the two lenses at 149mm. The Rokinon 85mm F1.8 with a length of 81mm, is 68mm shorter. Besides being longer, the Sony FE 70-200mm F4 G OSS II also has a larger diameter of 82mm compared to the Rokinon 85mm F1.8's 68mm 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. Rokinon 85mm F1.8 weighs 344g, 56% (450g) lighter than the Sony FE 70-200mm F4 G OSS II's weight of 794g.
Filter Threads
The Sony FE 70-200mm F4 G OSS II has a filter size of 72mm whereas the Rokinon 85mm F1.8 has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Sony FE 70-200mm F4 G OSS II:
And these are the 62mm filters that we recommend for the Rokinon 85mm F1.8:
Lens Mounts
Both the Sony FE 70-200mm F4 G OSS II and the Rokinon 85mm F1.8 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.
Rokinon 85mm F1.8 is also available in Canon EF-M and Fujifilm X mounts.
Focal Range
Sony FE 70-200mm F4 G OSS II has a focal range of 70-200mm 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
105 - 300mm.
On the other hand, the Rokinon 85mm F1.8 is a prime lens with fixed focal lenght of 85mm which has an effective (full-frame 35mm equivalent) focal range of 127.5mm when used on a APS-C / DX format camera.
