The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 150-500mm F5-6.3 and the Pentax 55-300mm F4.0-5.8 ED 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 150-500mm F5-6.3 is the longer of the two lenses at 252mm. The Pentax 55-300mm F4.0-5.8 ED with a length of 112mm, is 140mm shorter. Besides being longer, the Sigma 150-500mm F5-6.3 also has a larger diameter of 95mm compared to the Pentax 55-300mm F4.0-5.8 ED's 71mm 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 55-300mm F4.0-5.8 ED weighs 440g, 75% (1340g) lighter than the Sigma 150-500mm F5-6.3's weight of 1780g.
Filter Threads
The Sigma 150-500mm F5-6.3 has a filter size of 86mm whereas the Pentax 55-300mm F4.0-5.8 ED 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 86mm filters that we recommend you to consider for the Sigma 150-500mm F5-6.3:
And these are the 58mm filters that we recommend for the Pentax 55-300mm F4.0-5.8 ED:
Lens Mounts
The Sigma 150-500mm F5-6.3 has the Pentax KAF3 lens mount whereas the Pentax 55-300mm F4.0-5.8 ED has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 150-500mm F5-6.3 is also available in the Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 150-500mm F5-6.3 has a focal range of 150-500mm and
3.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
225 - 750mm.
On the other hand, the Pentax 55-300mm F4.0-5.8 ED has a focal range of 55-300mm and 5.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 82.5-450mm when used on a APS-C / DX format camera.
