The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-FA 35mm F2 AL and the Tamron AF 28-80mm f3.5-5.6 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 AF 28-80mm f3.5-5.6 is the longer of the two lenses at 70mm. The HD Pentax-FA 35mm F2 AL with a length of 45mm, is 25mm shorter. Besides being longer, the Tamron AF 28-80mm f3.5-5.6 also has a larger diameter of 72mm compared to the HD Pentax-FA 35mm F2 AL's 64mm 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. HD Pentax-FA 35mm F2 AL weighs 193g, which means it is 44g (18%) lighter than the Tamron AF 28-80mm f3.5-5.6 which has a weight of 237g.
Filter Threads
The HD Pentax-FA 35mm F2 AL has a filter size of 49mm whereas the Tamron AF 28-80mm f3.5-5.6 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 HD Pentax-FA 35mm F2 AL:
And these are the 58mm filters that we recommend for the Tamron AF 28-80mm f3.5-5.6:
Lens Mounts
Both the HD Pentax-FA 35mm F2 AL and the Tamron AF 28-80mm f3.5-5.6 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 Mono, Pentax KF and Pentax K-3 III.
Tamron AF 28-80mm f3.5-5.6 is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
HD Pentax-FA 35mm F2 AL is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
52.5mm.
On the other hand, the Tamron AF 28-80mm f3.5-5.6 has a focal range of 28-80mm and 2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 120mm.
