The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 90mm f2.8 Macro and the Pentax D-FA 100mm F2.8 Macro WR 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. Tamron 90mm f2.8 Macro is the longer of the two lenses at 97mm. The Pentax D-FA 100mm F2.8 Macro WR with a length of 81mm, is 16mm shorter. Besides being longer, the Tamron 90mm f2.8 Macro also has a larger diameter of 72mm compared to the Pentax D-FA 100mm F2.8 Macro WR's 65mm 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 WR weighs 340g, 16% (65g) lighter than the Tamron 90mm f2.8 Macro's weight of 405g.
Below you can find the dimension and weight table of the Macro Prime Lenses in Pentax KAF Mount for size comparison purposes.
Macro Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
The Tamron 90mm f2.8 Macro has a filter size of 55mm whereas the Pentax D-FA 100mm F2.8 Macro WR 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 55mm filters that we recommend you to consider for the Tamron 90mm f2.8 Macro:
And these are the 49mm filters that we recommend for the Pentax D-FA 100mm F2.8 Macro WR:
Lens Mounts
Both the Tamron 90mm f2.8 Macro and the Pentax D-FA 100mm F2.8 Macro WR 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.
Tamron 90mm f2.8 Macro is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
Tamron 90mm f2.8 Macro is a prime lens with fixed focal lenght of 90mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
135mm.
On the other hand, the Pentax D-FA 100mm F2.8 Macro WR 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.