The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 90mm f2.8 Macro 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 90mm f2.8 Macro is the longer of the two lenses at 97mm. The Sigma 18-250mm F3.5-6.3 DC OS HSM with a length of 89mm, is 8mm shorter. On the other hand, the Sigma 18-250mm F3.5-6.3 DC OS HSM has a larger diameter of 74mm compared to the Tamron 90mm f2.8 Macro's 72mm 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 90mm f2.8 Macro weighs 405g, which means it is 65g (13%) lighter than the Sigma 18-250mm F3.5-6.3 DC OS HSM which has a weight of 470g.
Filter Threads
The Tamron 90mm f2.8 Macro has a filter size of 55mm 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 55mm filters that we recommend you to consider for the Tamron 90mm f2.8 Macro:
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 90mm f2.8 Macro has the Nikon F (FX) lens mount whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has the Sony Alpha 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 Sony A68, Sony A77 II and Sony A58 for the Sony Alpha Mount.
Tamron 90mm f2.8 Macro is also available in the Canon EF , Sony Alpha and Pentax KAF mounts.
Sigma 18-250mm F3.5-6.3 DC OS HSM is also available in Canon EF , Nikon F (DX), Pentax KAF3, Sigma SA, Canon EF, Nikon F (DX), Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Tamron 90mm f2.8 Macro is a prime lens with fixed focal lenght of 90mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
135mm.
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.
