The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 28-75mm F2.8 Di III and the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye 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 28-75mm F2.8 Di III is the longer of the two lenses at 118mm. The HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye with a length of 70mm, is 48mm shorter. Besides being longer, the Tamron 28-75mm F2.8 Di III also has a larger diameter of 76mm compared to the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye'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. HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye weighs 317g, 41% (223g) lighter than the Tamron 28-75mm F2.8 Di III's weight of 540g.
Lens Mounts
The Tamron 28-75mm F2.8 Di III has the Nikon Z lens mount whereas the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon ZR, Nikon Z5 II and RED Komodo-X 6K Z for the Nikon Z Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron 28-75mm F2.8 Di III is also available in the Sony E and Sony E mounts.
Focal Range
Tamron 28-75mm F2.8 Di III has a focal range of 28-75mm and
2.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
42 - 112.5mm.
On the other hand, the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye has a focal range of 10-17mm and 1.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-25.5mm when used on a APS-C / DX format camera.
