The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 16-300mm f3.5-6.3 II VC PZD 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 an important deciding factor when comparing two lenses. Tamron 16-300mm f3.5-6.3 II VC PZD is the longer of the two lenses at 100mm. The Sigma 18-250mm F3.5-6.3 DC OS HSM with a length of 89mm, is 11mm shorter. Besides being longer, the Tamron 16-300mm f3.5-6.3 II VC PZD 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 as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 18-250mm F3.5-6.3 DC OS HSM weighs 470g, 12% (70g) lighter than the Tamron 16-300mm f3.5-6.3 II VC PZD's weight of 540g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Sony Alpha Mount for size comparison purposes.
SuperZoom Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both the Tamron 16-300mm f3.5-6.3 II VC PZD and the Sigma 18-250mm F3.5-6.3 DC OS HSM has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Tamron 16-300mm f3.5-6.3 II VC PZD is also available in Canon EF and Nikon F (DX) 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 16-300mm f3.5-6.3 II VC PZD has a focal range of 16-300mm and 18.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-450mm when used on a APS-C / DX format camera. 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.