The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic Leica 35-100mm f2.8 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. Panasonic Leica 35-100mm f2.8 is the longer of the two lenses at 100mm. The Pentax FA 31mm F1.8 L with a length of 69mm, is 31mm shorter. Besides being longer, the Panasonic Leica 35-100mm f2.8 also has a larger diameter of 67mm 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. Pentax FA 31mm F1.8 L weighs 345g, 4% (15g) lighter than the Panasonic Leica 35-100mm f2.8's weight of 360g.
Filter Threads
Both the Panasonic Leica 35-100mm f2.8 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 Panasonic Leica 35-100mm f2.8 has the Micro Four Thirds 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 OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Focal Range
Panasonic Leica 35-100mm f2.8 has a focal range of 35-100mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
70-200mm when used on a FourThirds 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.
