The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 18-250mm f3.5-6.3 II LD and the Sigma 18-250mm F3.5-6.3 DC OS HSM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 18-250mm F3.5-6.3 DC OS HSM is the longer of the two lenses at 101mm. The Tamron AF 18-250mm f3.5-6.3 II LD with a length of 84mm is 17mm shorter. Besides being longer, the Sigma 18-250mm F3.5-6.3 DC OS HSM also has a larger diameter of 79mm compared to Tamron AF 18-250mm f3.5-6.3 II LD's 74mm diameter.
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. Tamron AF 18-250mm f3.5-6.3 II LD weighs 430g, which means it is 198g (31%) lighter than the Sigma 18-250mm F3.5-6.3 DC OS HSM which has a weight of 628g.
Below you can find the dimension and weight table of the 'SuperZoom Lenses in Canon EF Mount for size comparison purposes.
SuperZoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Tamron AF 18-250mm f3.5-6.3 II LD and Sigma 18-250mm F3.5-6.3 DC OS HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Tamron AF 18-250mm f3.5-6.3 II LD is also available in Nikon F (DX) , 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, Sony Alpha, Sigma SA, Nikon F (DX), Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Both lenses have the same focal range of 18-250mm and the fastest aperture of F3.5 - F6.3.