The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 20mm F1.8 and the Samyang 12mm f2.0 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Samyang 12mm f2.0 with a length of 59mm, is 29mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to the Samyang 12mm f2.0's 73mm 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 12mm f2.0 weighs 260g, 47% (237g) lighter than the Samyang 20mm F1.8's weight of 497g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Canon EF-M Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon EF-M Mount for Size Comparison
Filter Threads
The Samyang 20mm F1.8 has a filter size of 77mm whereas the Samyang 12mm f2.0 has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Samyang 20mm F1.8:
And these are the 67mm filters that we recommend for the Samyang 12mm f2.0:
Lens Mounts
Both the Samyang 20mm F1.8 and the Samyang 12mm f2.0 has the same Canon EF-M lens mount. Some of the latest released cameras that are compatible with the Canon EF-M lenses are Canon M50 II, Canon M200 and Canon M6 MII.
Samyang 20mm F1.8 is also available in the Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Samyang 12mm f2.0 is also available in Fujifilm X , Micro Four Thirds, Sony E and Samsung NX mounts.
Focal Range
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 a 35mm (FF) equivalent of
32mm.
On the other hand, the Samyang 12mm f2.0 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of 18mm when used on a APS-C / DX format camera.
