The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina 16.5-135mm f3.5-5.6 DX and the Sigma 18-125mm F3.8-5.6 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 18-125mm F3.8-5.6 DC OS HSM is the longer of the two lenses at 89mm. The Tokina 16.5-135mm f3.5-5.6 DX with a length of 78mm, is 11mm shorter. On the other hand, the Tokina 16.5-135mm f3.5-5.6 DX has a larger diameter of 84mm compared to the Sigma 18-125mm F3.8-5.6 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. Sigma 18-125mm F3.8-5.6 DC OS HSM weighs 490g, 19% (120g) lighter than the Tokina 16.5-135mm f3.5-5.6 DX's weight of 610g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Nikon F (DX) Mount for size comparison purposes.
Superzoom Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
The Tokina 16.5-135mm f3.5-5.6 DX has a filter size of 77mm whereas the Sigma 18-125mm F3.8-5.6 DC OS HSM 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 77mm filters that we recommend you to consider for the Tokina 16.5-135mm f3.5-5.6 DX:
And these are the 67mm filters that we recommend for the Sigma 18-125mm F3.8-5.6 DC OS HSM:
Lens Mounts
Both the Tokina 16.5-135mm f3.5-5.6 DX and the Sigma 18-125mm F3.8-5.6 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.
Tokina 16.5-135mm f3.5-5.6 DX is also available in the Canon EF mount.
Sigma 18-125mm F3.8-5.6 DC OS HSM is also available in Canon EF and Sigma SA mounts.
Focal Range
Tokina 16.5-135mm f3.5-5.6 DX has a focal range of 17-135mm and
7.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-202.5mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 18-125mm F3.8-5.6 DC OS HSM has a focal range of 18-125mm and 6.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-187.5mm when used on a APS-C / DX format camera.
