The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Zeiss Milvus 18mm F2.8 and the Samyang 20mm F1.8 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Zeiss Milvus 18mm F2.8 is the longer of the two lenses at 93mm. The Samyang 20mm F1.8 with a length of 88mm is 5mm shorter. On the other hand, the Samyang 20mm F1.8 has a larger diameter of 83mm compared to Zeiss Milvus 18mm F2.8's 73mm diameter.
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. Samyang 20mm F1.8 weighs 497g, 31% (224g) lighter than the Zeiss Milvus 18mm F2.8's weight of 721g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Canon EF Mount for size comparison purposes.
Wideangle Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Zeiss Milvus 18mm F2.8 and Samyang 20mm F1.8 has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Zeiss Milvus 18mm F2.8 is also available in Nikon F (FX) mount.
Samyang 20mm F1.8 is also available in Canon EF-M , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Zeiss Milvus 18mm F2.8 is a prime lens with fixed focal lenght of 18mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 28.8mm.
Samyang 20mm F1.8 is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 32mm.