The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina 16-50mm f2.8 DX and the Sigma 18-50mm F2.8-4.5 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. Tokina 16-50mm f2.8 DX is the longer of the two lenses at 97mm. The Sigma 18-50mm F2.8-4.5 DC OS HSM with a length of 89mm, is 8mm shorter. Besides being longer, the Tokina 16-50mm f2.8 DX also has a larger diameter of 84mm compared to the Sigma 18-50mm F2.8-4.5 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 18-50mm F2.8-4.5 DC OS HSM weighs 395g, 35% (215g) lighter than the Tokina 16-50mm f2.8 DX's weight of 610g.
Filter Threads
The Tokina 16-50mm f2.8 DX has a filter size of 77mm whereas the Sigma 18-50mm F2.8-4.5 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 16-50mm f2.8 DX:
And these are the 67mm filters that we recommend for the Sigma 18-50mm F2.8-4.5 DC OS HSM:
Lens Mounts
Both the Tokina 16-50mm f2.8 DX and the Sigma 18-50mm F2.8-4.5 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 16-50mm f2.8 DX is also available in the Canon EF mount.
Sigma 18-50mm F2.8-4.5 DC OS HSM is also available in Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Tokina 16-50mm f2.8 DX has a focal range of 16-50mm and
3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
24-75mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 18-50mm F2.8-4.5 DC OS HSM has a focal range of 18-50mm and 2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-75mm when used on a APS-C / DX format camera.
