The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 18-270mm f3.5-6.3 II VC LD and the Sigma 18-300 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 18-300 F3.5-6.3 DC OS HSM is the longer of the two lenses at 102mm. The Tamron AF 18-270mm f3.5-6.3 II VC LD with a length of 101mm, is 1mm shorter. On the other hand, the Tamron AF 18-270mm f3.5-6.3 II VC LD has a larger diameter of 80mm 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. Tamron AF 18-270mm f3.5-6.3 II VC LD weighs 560g, which means it is 25g (4%) lighter than the Sigma 18-300 F3.5-6.3 DC OS HSM which has a weight of 585g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Nikon F (DX) Mount for size comparison purposes.
Super Telephoto Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
Both the Tamron AF 18-270mm f3.5-6.3 II VC LD and the Sigma 18-300 F3.5-6.3 DC OS HSM have the same Filter thread size of 72mm.
Below are links to the 72mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Tamron AF 18-270mm f3.5-6.3 II VC LD and the Sigma 18-300 F3.5-6.3 DC OS HSM has the same Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (DX) lenses are Nikon D3500, Nikon D7500 and Nikon D5600.
Tamron AF 18-270mm f3.5-6.3 II VC LD is also available in Canon EF mount.
Sigma 18-300 F3.5-6.3 DC OS HSM is also available in Canon EF , Pentax KAF3, Sigma SA and Sony Alpha mounts.
Focal Range
Tamron AF 18-270mm f3.5-6.3 II VC LD has a focal range of 18-270mm and
15.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-405mm when used on a APS-C / DX format camera.
On the other hand, the 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.