The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax-D FA 85mm F1.4 ED SDM AW and the Tamron AF 70-300mm f4-5.6 LD 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-D FA 85mm F1.4 ED SDM AW is the longer of the two lenses at 124mm. The Tamron AF 70-300mm f4-5.6 LD with a length of 117mm, is 7mm shorter. Besides being longer, the Pentax-D FA 85mm F1.4 ED SDM AW also has a larger diameter of 95mm compared to the Tamron AF 70-300mm f4-5.6 LD's 77mm 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. Tamron AF 70-300mm f4-5.6 LD weighs 435g, 65% (820g) lighter than the Pentax-D FA 85mm F1.4 ED SDM AW's weight of 1255g.
Filter Threads
The Pentax-D FA 85mm F1.4 ED SDM AW has a filter size of 82mm whereas the Tamron AF 70-300mm f4-5.6 LD has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Pentax-D FA 85mm F1.4 ED SDM AW:
And these are the 62mm filters that we recommend for the Tamron AF 70-300mm f4-5.6 LD:
Lens Mounts
The Pentax-D FA 85mm F1.4 ED SDM AW has the Pentax KAF4 lens mount whereas the Tamron AF 70-300mm f4-5.6 LD has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF4 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron AF 70-300mm f4-5.6 LD is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
Pentax-D FA 85mm F1.4 ED SDM AW 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 Tamron AF 70-300mm f4-5.6 LD has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 105 - 450mm.
