The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus 17mm F1.2 Pro 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.Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Olympus 17mm F1.2 Pro with a length of 87mm is 1mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to Olympus 17mm F1.2 Pro's 68mm 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. Olympus 17mm F1.2 Pro weighs 390g, which means it is 107g (21%) lighter than the Samyang 20mm F1.8 which has a weight of 497g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Wideangle Prime Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both Olympus 17mm F1.2 Pro and Samyang 20mm F1.8 has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-5, Panasonic GH6 and OM System OM-1.
Samyang 20mm F1.8 is also available in Canon EF , Canon EF-M, Fujifilm X, Nikon F (FX), Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Olympus 17mm F1.2 Pro is a prime lens with fixed focal lenght of 17mm which has an effective (full-frame 35mm equivalent) focal range of 34mm when used on a FourThirds format camera. Samyang 20mm F1.8 is a prime lens with fixed focal lenght of 20mm.