The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Rokinon 14mm f2.8 and the Panasonic 20mm F1.7 II ASPH 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. Rokinon 14mm f2.8 is the longer of the two lenses at 96mm. The Panasonic 20mm F1.7 II ASPH with a length of 26mm, is 70mm shorter. Besides being longer, the Rokinon 14mm f2.8 also has a larger diameter of 87mm compared to the Panasonic 20mm F1.7 II ASPH's 63mm 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. Panasonic 20mm F1.7 II ASPH weighs 87g, 84% (465g) lighter than the Rokinon 14mm f2.8's weight of 552g.
Lens Mounts
The Rokinon 14mm f2.8 has the Four Thirds lens mount whereas the Panasonic 20mm F1.7 II ASPH has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Olympus E-5, Olympus E-600 and Olympus E-620 for the Four Thirds Mount and OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount.
Rokinon 14mm f2.8 is also available in the Canon EF , Nikon F (FX), Pentax KAF, Sony Alpha and Samsung NX mounts.
Focal Range
Rokinon 14mm f2.8 is a prime lens with fixed focal lenght of 14mm.
On the other hand, the Panasonic 20mm F1.7 II ASPH is a prime lens with fixed focal lenght of 20mm which has an effective (full-frame 35mm equivalent) focal range of 40mm when used on a FourThirds format camera.
