The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica TL 35mm F1.4 ASPH 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. Leica TL 35mm F1.4 ASPH is the longer of the two lenses at 77mm. The Pentax FA 31mm F1.8 L with a length of 69mm, is 8mm shorter. Besides being longer, the Leica TL 35mm F1.4 ASPH also has a larger diameter of 70mm 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. Leica TL 35mm F1.4 ASPH weighs 128g, which means it is 217g (62%) lighter than the Pentax FA 31mm F1.8 L which has a weight of 345g.
Filter Threads
The Leica TL 35mm F1.4 ASPH has a filter size of 60mm whereas the Pentax FA 31mm F1.8 L has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 60mm filters that we recommend you to consider for the Leica TL 35mm F1.4 ASPH:
And these are the 58mm filters that we recommend for the Pentax FA 31mm F1.8 L:
Lens Mounts
The Leica TL 35mm F1.4 ASPH has the Leica TL 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 , and for the Leica TL Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Focal Range
Leica TL 35mm F1.4 ASPH is a prime lens with fixed focal lenght of 35mm which has an effective (full-frame 35mm equivalent) focal range of
52.5mm when used on a APS-C / DX format camera.
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.