The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang AF 75mm F1.8 FE and the Zeiss Otus 85mm F1.4 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. Zeiss Otus 85mm F1.4 is the longer of the two lenses at 138mm. The Samyang AF 75mm F1.8 FE with a length of 69mm, is 69mm shorter. Besides being longer, the Zeiss Otus 85mm F1.4 also has a larger diameter of 101mm compared to the Samyang AF 75mm F1.8 FE'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 AF 75mm F1.8 FE weighs 230g, which means it is 970g (80%) lighter than the Zeiss Otus 85mm F1.4 which has a weight of 1200g.
Filter Threads
The Samyang AF 75mm F1.8 FE has a filter size of 58mm whereas the Zeiss Otus 85mm F1.4 has a 86mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Samyang AF 75mm F1.8 FE:
And these are the 86mm filters that we recommend for the Zeiss Otus 85mm F1.4:
Lens Mounts
The Samyang AF 75mm F1.8 FE has the Sony E lens mount whereas the Zeiss Otus 85mm F1.4 has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Sony A9 III, Sony A7C Mark II and Sony A7CR for the Sony E Mount and Canon 1D X III, Canon 6D MII and Canon 5D MIV for the Canon EF Mount.
Zeiss Otus 85mm F1.4 is also available in Nikon F (FX) mount.
Focal Range
Samyang AF 75mm F1.8 FE is a prime lens with fixed focal lenght of 75mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
112.5mm.
On the other hand, the Zeiss Otus 85mm F1.4 is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 136mm.