The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Carl Zeiss Planar T1,4/85 and the Pentax D-FA 100mm F2.8 Macro 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 T1,4/85 is the longer of the two lenses at 85mm. The Pentax D-FA 100mm F2.8 Macro with a length of 81mm, is 4mm shorter. Besides being longer, the Carl Zeiss Planar T1,4/85 also has a larger diameter of 78mm compared to the Pentax D-FA 100mm 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 100mm F2.8 Macro weighs 345g, 50% (355g) lighter than the Carl Zeiss Planar T1,4/85's weight of 700g.
Filter Threads
The Carl Zeiss Planar T1,4/85 has a filter size of 72mm whereas the Pentax D-FA 100mm F2.8 Macro has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Carl Zeiss Planar T1,4/85:
And these are the 49mm filters that we recommend for the Pentax D-FA 100mm F2.8 Macro:
Lens Mounts
Both the Carl Zeiss Planar T1,4/85 and the Pentax D-FA 100mm F2.8 Macro has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Carl Zeiss Planar T1,4/85 is also available in Canon EF and Nikon F (FX) mounts.
Focal Range
Carl Zeiss Planar T1,4/85 is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
127.5mm.
On the other hand, the Pentax D-FA 100mm F2.8 Macro is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 150mm.