The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 18-250mm F3.5-6.3 and the Sigma 18-250mm F3.5-6.3 DC OS HSM 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. Sigma 18-250mm F3.5-6.3 DC OS HSM is the longer of the two lenses at 89mm. The Pentax 18-250mm F3.5-6.3 with a length of 86mm, is 3mm shorter. On the other hand, the Pentax 18-250mm F3.5-6.3 has a larger diameter of 75mm compared to the Sigma 18-250mm F3.5-6.3 DC OS HSM's 74mm 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 18-250mm F3.5-6.3 weighs 455g, which means it is 15g (3%) lighter than the Sigma 18-250mm F3.5-6.3 DC OS HSM which has a weight of 470g.
Filter Threads
The Pentax 18-250mm F3.5-6.3 has a filter size of 62mm whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Pentax 18-250mm F3.5-6.3:
And these are the 72mm filters that we recommend for the Sigma 18-250mm F3.5-6.3 DC OS HSM:
Lens Mounts
The Pentax 18-250mm F3.5-6.3 has the Pentax KAF lens mount whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and , and for the Pentax KAF3 Mount.
Sigma 18-250mm F3.5-6.3 DC OS HSM is also available in Canon EF , Nikon F (DX), Sony Alpha, Sigma SA, Canon EF, Nikon F (DX), Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Both lenses have the same focal range of
18-250mm and the fastest aperture of
F3.5 - F6.3.