The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 28-80mm f3.5-5.6 and the Pentax 35mm F2.4 AL 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 Pentax 35mm F2.4 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 Pentax 35mm F2.4 AL's 63mm 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 35mm F2.4 AL weighs 124g, 47% (113g) lighter than the Tamron AF 28-80mm f3.5-5.6's weight of 237g.
Filter Threads
The Tamron AF 28-80mm f3.5-5.6 has a filter size of 58mm whereas the Pentax 35mm F2.4 AL 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 58mm filters that we recommend you to consider for the Tamron AF 28-80mm f3.5-5.6:
And these are the 49mm filters that we recommend for the Pentax 35mm F2.4 AL:
Lens Mounts
Both the Tamron AF 28-80mm f3.5-5.6 and the Pentax 35mm F2.4 AL 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 the Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
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.
On the other hand, the Pentax 35mm F2.4 AL is a prime lens with fixed focal lenght of 35mm which has an effective (full-frame 35mm equivalent) focal range of 52.5mm when used on a APS-C / DX format camera.
