The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 70-300mm F4-5.6 DG OS and the Nikon 18-300mm F3.5-6.3G ED VR 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 70-300mm F4-5.6 DG OS is the longer of the two lenses at 126mm. The Nikon 18-300mm F3.5-6.3G ED VR with a length of 99mm, is 27mm shorter. On the other hand, the Nikon 18-300mm F3.5-6.3G ED VR has a larger diameter of 79mm compared to the Sigma 70-300mm F4-5.6 DG OS's 77mm 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. Nikon 18-300mm F3.5-6.3G ED VR weighs 550g, 9% (60g) lighter than the Sigma 70-300mm F4-5.6 DG OS's weight of 610g.
Filter Threads
The Sigma 70-300mm F4-5.6 DG OS has a filter size of 58mm whereas the Nikon 18-300mm F3.5-6.3G ED VR has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Sigma 70-300mm F4-5.6 DG OS:
And these are the 67mm filters that we recommend for the Nikon 18-300mm F3.5-6.3G ED VR:
Lens Mounts
The Sigma 70-300mm F4-5.6 DG OS has the Nikon F (FX) lens mount whereas the Nikon 18-300mm F3.5-6.3G ED VR has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 70-300mm F4-5.6 DG OS is also available in Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 70-300mm F4-5.6 DG OS has a focal range of 70-300mm and
4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 450mm.
On the other hand, the Nikon 18-300mm F3.5-6.3G ED VR 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.