The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-D FA 50mm F1.4 SDM AW and the Pentax 50mm F1.8 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.HD Pentax-D FA 50mm F1.4 SDM AW is the longer of the two lenses at 106mm. The Pentax 50mm F1.8 with a length of 39mm is 67mm shorter. Besides being longer, the HD Pentax-D FA 50mm F1.4 SDM AW also has a larger diameter of 80mm compared to Pentax 50mm F1.8's 63mm 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. Pentax 50mm F1.8 weighs 122g, 86% (788g) lighter than the HD Pentax-D FA 50mm F1.4 SDM AW's weight of 910g.
Both HD Pentax-D FA 50mm F1.4 SDM AW has the Pentax KAF3 lens mount whereas the Pentax 50mm F1.8 has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF3 Mount and Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF Mount.