The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 18-300mm F3.5-6.3 Di 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 18-300mm F3.5-6.3 Di is the longer of the two lenses at 126mm. The Sigma 18-250mm F3.5-6.3 DC OS HSM with a length of 101mm, is 25mm 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 18-300mm F3.5-6.3 Di'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. Tamron 18-300mm F3.5-6.3 Di weighs 620g, which means it is 8g (1%) lighter than the Sigma 18-250mm F3.5-6.3 DC OS HSM which has a weight of 628g.
Filter Threads
The Tamron 18-300mm F3.5-6.3 Di 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 18-300mm F3.5-6.3 Di:
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 18-300mm F3.5-6.3 Di has the Sony E 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 Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Sony A68, Sony A77 II and Sony A58 for the Sony Alpha Mount.
Tamron 18-300mm F3.5-6.3 Di is also available in the Fujifilm X 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 Sigma SA mounts.
Focal Range
Tamron 18-300mm F3.5-6.3 Di has a focal range of 18-300mm and
16.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-450mm 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.
