The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 135mm F2.0 ED UMC and the Samyang 135mm F2.0 ED UMC for their suitability to various photography scenarios:
Size and Weight Comparison

Samyang 135mm F2.0 ED UMC vs Samyang 135mm F2.0 ED UMC Lenses Size Comparison
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.
Filter Threads
Both the Samyang 135mm F2.0 ED UMC and the Samyang 135mm F2.0 ED UMC have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Samyang 135mm F2.0 ED UMC has the Sony Alpha lens mount whereas the Samyang 135mm F2.0 ED UMC has the Canon EF-M lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Sony Alpha Mount and Canon M50 II, Canon M200 and Canon M6 MII for the Canon EF-M Mount.
Samyang 135mm F2.0 ED UMC is also available in the Canon EF , Canon EF-M, Four Thirds, Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX and Sony E mounts.
Samyang 135mm F2.0 ED UMC is also available in Canon EF , Four Thirds, Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Both lenses have the same focal range of
135mm and the fastest aperture of
F2.