The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-300 F3.5-6.3 DC OS HSM and the Sigma 300-800mm F5.6 EX DG 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 300-800mm F5.6 EX DG HSM is the longer of the two lenses at 544mm. The Sigma 18-300 F3.5-6.3 DC OS HSM with a length of 102mm, is 442mm shorter. Besides being longer, the Sigma 300-800mm F5.6 EX DG HSM also has a larger diameter of 157mm compared to the Sigma 18-300 F3.5-6.3 DC OS HSM's 79mm 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 18-300 F3.5-6.3 DC OS HSM weighs 585g, which means it is 5295g (90%) lighter than the Sigma 300-800mm F5.6 EX DG HSM which has a weight of 5880g.
Filter Threads
The Sigma 18-300 F3.5-6.3 DC OS HSM has a filter size of 72mm whereas the Sigma 300-800mm F5.6 EX DG HSM has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Sigma 18-300 F3.5-6.3 DC OS HSM:
And these are the 46mm filters that we recommend for the Sigma 300-800mm F5.6 EX DG HSM:
Lens Mounts
The Sigma 18-300 F3.5-6.3 DC OS HSM has the Nikon F (DX) lens mount whereas the Sigma 300-800mm F5.6 EX DG HSM has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 18-300 F3.5-6.3 DC OS HSM is also available in the Canon EF , Pentax KAF3, Sigma SA and Sony Alpha mounts.
Sigma 300-800mm F5.6 EX DG HSM is also available in Sigma SA and Canon EF mounts.
Focal Range
Sigma 18-300 F3.5-6.3 DC OS HSM has a focal range of 18-300mm and
16.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-450mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 300-800mm F5.6 EX DG HSM has a focal range of 300-800mm 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 450 - 1200mm.
