The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 24mm f1.4 and the Samyang 12mm f2.0 for their suitability to various photography scenarios:
Size and Weight 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. Samyang 12mm f2.0 weighs 260g, 55% (320g) lighter than the Samyang 24mm f1.4's weight of 580g.
Filter Threads
The Samyang 24mm f1.4 has a filter size of 77mm whereas the Samyang 12mm f2.0 has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Samyang 24mm f1.4:
And these are the 67mm filters that we recommend for the Samyang 12mm f2.0:
Lens Mounts
Both the Samyang 24mm f1.4 and the Samyang 12mm f2.0 has the same Samsung NX lens mount. Some of the latest released cameras that are compatible with the Samsung NX lenses are Samsung NX500, Samsung NX1 and Samsung NX3000.
Samyang 24mm f1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF, Sony Alpha and Sony E mounts.
Samyang 12mm f2.0 is also available in Canon EF-M , Fujifilm X, Micro Four Thirds and Sony E mounts.
Focal Range
Samyang 24mm f1.4 is a prime lens with fixed focal lenght of 24mm.
On the other hand, the Samyang 12mm f2.0 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of 18mm when used on a APS-C / DX format camera.