The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samsung 20mm F2.8 Pancake and the Rokinon 35mm f1.4 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 35mm f1.4 is the longer of the two lenses at 112mm. The Samsung 20mm F2.8 Pancake with a length of 25mm, is 87mm shorter. Besides being longer, the Rokinon 35mm f1.4 also has a larger diameter of 63mm compared to the Samsung 20mm F2.8 Pancake's 62mm 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. Samsung 20mm F2.8 Pancake weighs 89g, which means it is 571g (86%) lighter than the Rokinon 35mm f1.4 which has a weight of 660g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Samsung NX Mount for size comparison purposes.
Wideangle Lenses in Samsung NX Mount for Size Comparison
Filter Threads
The Samsung 20mm F2.8 Pancake has a filter size of 43mm whereas the Rokinon 35mm f1.4 has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 43mm filters that we recommend you to consider for the Samsung 20mm F2.8 Pancake:
And these are the 77mm filters that we recommend for the Rokinon 35mm f1.4:
Lens Mounts
Both the Samsung 20mm F2.8 Pancake and the Rokinon 35mm f1.4 has the same Samsung NX lens mount. Some of the latest released cameras that are compatible with the Samsung NX lenses are Samsung NX1, Samsung NX3000 and Samsung NX30.
Rokinon 35mm f1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF and Sony Alpha mounts.
Focal Range
Samsung 20mm F2.8 Pancake is a prime lens with fixed focal lenght of 20mm which has an effective (full-frame 35mm equivalent) focal range of
30mm when used on a APS-C / DX format camera.
On the other hand, the Rokinon 35mm f1.4 is a prime lens with fixed focal lenght of 35mm.