The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 70-210mm F4 Di VC USD and the Sigma 18-250mm 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. Tamron 70-210mm F4 Di VC USD is the longer of the two lenses at 175mm. The Sigma 18-250mm F3.5-6.3 DC OS HSM with a length of 101mm, is 74mm shorter. On the other hand, the Sigma 18-250mm F3.5-6.3 DC OS HSM has a larger diameter of 79mm compared to the Tamron 70-210mm F4 Di VC USD's 76mm 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 18-250mm F3.5-6.3 DC OS HSM weighs 628g, 26% (231g) lighter than the Tamron 70-210mm F4 Di VC USD's weight of 859g.
Filter Threads
The Tamron 70-210mm F4 Di VC USD has a filter size of 67mm whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 70-210mm F4 Di VC USD:
And these are the 72mm filters that we recommend for the Sigma 18-250mm F3.5-6.3 DC OS HSM:
Lens Mounts
The Tamron 70-210mm F4 Di VC USD has the Nikon F (FX) lens mount whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has the Sigma SA 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 Sigma SD1 Merrill, Sigma SD1 and for the Sigma SA Mount.
Tamron 70-210mm F4 Di VC USD is also available in the Canon EF mount.
Sigma 18-250mm F3.5-6.3 DC OS HSM is also available in Canon EF , Nikon F (DX), Pentax KAF3, Sony Alpha, Sigma SA, Canon EF, Nikon F (DX), Pentax KAF3 and Sony Alpha mounts.
Focal Range
Tamron 70-210mm F4 Di VC USD has a focal range of 70-210mm and
3.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 315mm.
On the other hand, the Sigma 18-250mm F3.5-6.3 DC OS HSM has a focal range of 18-250mm and 13.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-375mm when used on a APS-C / DX format camera.
