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 300mm f6.3 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 135mm F2.0 ED UMC is the longer of the two lenses at 122mm. The Samyang 300mm f6.3 with a length of 74mm, is 48mm shorter. Besides being longer, the Samyang 135mm F2.0 ED UMC also has a larger diameter of 82mm compared to the Samyang 300mm f6.3'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 300mm f6.3 weighs 318g, 61% (512g) lighter than the Samyang 135mm F2.0 ED UMC's weight of 830g.
Lens Mounts
Both the Samyang 135mm F2.0 ED UMC and the Samyang 300mm f6.3 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 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.
Samyang 300mm f6.3 is also available in Fujifilm X , Micro Four Thirds and Sony E mounts.
Focal Range
Samyang 135mm F2.0 ED UMC is a prime lens with fixed focal lenght of 135mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
216mm.
On the other hand, the Samyang 300mm f6.3 is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of 450mm when used on a APS-C / DX format camera.