The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D-FA 50mm F2.8 Macro and the Pentax DA 55mm F1.4 SDM 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 DA 55mm F1.4 SDM is the longer of the two lenses at 66mm. The Pentax D-FA 50mm F2.8 Macro with a length of 60mm, is 6mm shorter. Besides being longer, the Pentax DA 55mm F1.4 SDM also has a larger diameter of 70mm compared to the Pentax D-FA 50mm F2.8 Macro's 68mm 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 D-FA 50mm F2.8 Macro weighs 265g, which means it is 110g (29%) lighter than the Pentax DA 55mm F1.4 SDM which has a weight of 375g.
Filter Threads
The Pentax D-FA 50mm F2.8 Macro has a filter size of 49mm whereas the Pentax DA 55mm F1.4 SDM 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 49mm filters that we recommend you to consider for the Pentax D-FA 50mm F2.8 Macro:
And these are the 58mm filters that we recommend for the Pentax DA 55mm F1.4 SDM:
Lens Mounts
The Pentax D-FA 50mm F2.8 Macro has the Pentax KAF lens mount whereas the Pentax DA 55mm F1.4 SDM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and , and for the Pentax KAF3 Mount.
Focal Range
Pentax D-FA 50mm F2.8 Macro 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 DA 55mm F1.4 SDM is a prime lens with fixed focal lenght of 55mm which has an effective (full-frame 35mm equivalent) focal range of 82.5mm when used on a APS-C / DX format camera.