The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 18-200mm F3.5-6.3 Di II VC 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 18-200mm F3.5-6.3 Di II VC 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. Besides being longer, the Tamron 18-200mm F3.5-6.3 Di II VC also has a larger diameter of 75mm compared to the Sigma 18-250mm F3.5-6.3 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. Tamron 18-200mm F3.5-6.3 Di II VC weighs 400g, which means it is 70g (14%) lighter than the Sigma 18-250mm F3.5-6.3 DC OS HSM which has a weight of 470g.
Filter Threads
The Tamron 18-200mm F3.5-6.3 Di II VC has a filter size of 62mm 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 62mm filters that we recommend you to consider for the Tamron 18-200mm F3.5-6.3 Di II VC:
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 18-200mm F3.5-6.3 Di II VC has the Canon EF lens mount whereas the Sigma 18-250mm F3.5-6.3 DC OS HSM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount and , and for the Pentax KAF3 Mount.
Tamron 18-200mm F3.5-6.3 Di II VC is also available in the Nikon F (DX) and Sony Alpha mounts.
Sigma 18-250mm F3.5-6.3 DC OS HSM is also available in Canon EF , Nikon F (DX), Sony Alpha, Sigma SA, Canon EF, Nikon F (DX), Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Tamron 18-200mm F3.5-6.3 Di II VC has a focal range of 18-200mm and
11.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
28.8-320mm when used on a APS-C / DX format camera.
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.
