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 10mm f2.8 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Samyang 10mm f2.8 with a length of 77mm, is 11mm shorter. On the other hand, the Samyang 10mm f2.8 has a larger diameter of 86mm compared to the Samyang 20mm F1.8's 83mm 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 20mm F1.8 weighs 497g, which means it is 83g (14%) lighter than the Samyang 10mm f2.8 which has a weight of 580g.
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
Lens Mounts
Both the Samyang 20mm F1.8 and the Samyang 10mm f2.8 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 Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Samyang 10mm f2.8 is also available in Canon EF , Fujifilm X, Nikon F (DX), Four Thirds and Micro Four Thirds 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 10mm f2.8 is a prime lens with fixed focal lenght of 10mm which has an effective (full-frame 35mm equivalent) focal range of 15mm when used on a APS-C / DX format camera.