The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Carl Zeiss Planar T1,4/50 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. Carl Zeiss Planar T1,4/50 is the longer of the two lenses at 69mm. The Pentax DA 55mm F1.4 SDM with a length of 66mm, is 3mm shorter. On the other hand, the Pentax DA 55mm F1.4 SDM has a larger diameter of 70mm compared to the Carl Zeiss Planar T1,4/50's 66mm 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. Carl Zeiss Planar T1,4/50 weighs 350g, which means it is 25g (6%) lighter than the Pentax DA 55mm F1.4 SDM which has a weight of 375g.
Filter Threads
Both the Carl Zeiss Planar T1,4/50 and the Pentax DA 55mm F1.4 SDM 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 Carl Zeiss Planar T1,4/50 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.
Carl Zeiss Planar T1,4/50 is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Carl Zeiss Planar T1,4/50 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.