The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-FA 31mm F1.8 Ltd and the Lensbaby Burnside 35 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Lensbaby Burnside 35 is the longer of the two lenses at 70mm. The HD Pentax-FA 31mm F1.8 Ltd with a length of 69mm is 1mm shorter. Besides being longer, the Lensbaby Burnside 35 also has a larger diameter of 70mm compared to HD Pentax-FA 31mm F1.8 Ltd's 65mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. HD Pentax-FA 31mm F1.8 Ltd weighs 341g, which means it is 33g (8%) lighter than the Lensbaby Burnside 35 which has a weight of 374g.
Both HD Pentax-FA 31mm F1.8 Ltd and Lensbaby Burnside 35 has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax KF, Pentax K-3 III and Pentax K-1 II.
Lensbaby Burnside 35 is also available in Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Samsung NX, Sony Alpha and Sony E mounts.
HD Pentax-FA 31mm F1.8 Ltd 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 an 35mm (FF) equivalent of 46.5mm.
Lensbaby Burnside 35 is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 52.5mm.