The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-18mm F2.8 DC DN C 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. HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye is the longer of the two lenses at 70mm. The Sigma 10-18mm F2.8 DC DN C with a length of 64mm, is 6mm shorter. On the other hand, the Sigma 10-18mm F2.8 DC DN C has a larger diameter of 72mm 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. Sigma 10-18mm F2.8 DC DN C weighs 250g, which means it is 67g (21%) lighter than the HD Pentax-DA 10-17mm F3.5-4.5 ED fisheye which has a weight of 317g.
Lens Mounts
The Sigma 10-18mm F2.8 DC DN C has the Fujifilm X 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 Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5 for the Fujifilm X Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 10-18mm F2.8 DC DN C is also available in the Sony E , Leica L and Canon RF mounts.
Focal Range
Sigma 10-18mm F2.8 DC DN C has a focal range of 10-18mm and
1.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-27mm when used on a APS-C / DX format camera.
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.
