The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 85mm F1.8 VC and the Sigma 70-200mm F2.8 EX DG HSM II 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 70-200mm F2.8 EX DG HSM II is the longer of the two lenses at 184mm. The Tamron 85mm F1.8 VC with a length of 91mm, is 93mm shorter. Besides being longer, the Sigma 70-200mm F2.8 EX DG HSM II also has a larger diameter of 87mm compared to the Tamron 85mm F1.8 VC's 85mm 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 85mm F1.8 VC weighs 700g, which means it is 690g (49%) lighter than the Sigma 70-200mm F2.8 EX DG HSM II which has a weight of 1390g.
Filter Threads
The Tamron 85mm F1.8 VC has a filter size of 67mm whereas the Sigma 70-200mm F2.8 EX DG HSM II has a 77mm 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 85mm F1.8 VC:
And these are the 77mm filters that we recommend for the Sigma 70-200mm F2.8 EX DG HSM II:
Lens Mounts
Both the Tamron 85mm F1.8 VC and the Sigma 70-200mm F2.8 EX DG HSM II has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tamron 85mm F1.8 VC is also available in Sony Alpha and Canon EF mounts.
Sigma 70-200mm F2.8 EX DG HSM II is also available in Canon EF , Four Thirds, Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Tamron 85mm F1.8 VC is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
127.5mm.
On the other hand, the Sigma 70-200mm F2.8 EX DG HSM II has a focal range of 70-200mm and 2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 105 - 300mm.