The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon 50mm f1.4G and the Pentax FA 31mm F1.8 L 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. Pentax FA 31mm F1.8 L is the longer of the two lenses at 69mm. The Nikon 50mm f1.4G with a length of 54mm, is 15mm shorter. On the other hand, the Nikon 50mm f1.4G has a larger diameter of 74mm compared to the Pentax FA 31mm F1.8 L'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. Nikon 50mm f1.4G weighs 290g, which means it is 55g (15%) lighter than the Pentax FA 31mm F1.8 L which has a weight of 345g.
Filter Threads
Both the Nikon 50mm f1.4G and the Pentax FA 31mm F1.8 L have the same Filter thread size of 58mm.
Below are links to the 58mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Nikon 50mm f1.4G has the Nikon F (FX) lens mount whereas the Pentax FA 31mm F1.8 L has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Focal Range
Nikon 50mm f1.4G is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the Pentax FA 31mm F1.8 L is a prime lens with fixed focal lenght of 31mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 46.5mm.
