The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 70-300mm f4-5.6 LD and the Sigma 70-300mm F4-5.6 DG OS 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 70-300mm F4-5.6 DG OS is the longer of the two lenses at 126mm. The Tamron AF 70-300mm f4-5.6 LD with a length of 117mm is 9mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 77mm.
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 70-300mm f4-5.6 LD weighs 435g, which means it is 175g (28%) lighter than the Sigma 70-300mm F4-5.6 DG OS which has a weight of 610g.
Below you can find the dimension and weight table of the 'Telephoto Zoom Lenses in Canon EF Mount for size comparison purposes.
Telephoto Zoom Lenses in Canon EF Mount for Size Comparison
Both Tamron AF 70-300mm f4-5.6 LD and Sigma 70-300mm F4-5.6 DG OS has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron AF 70-300mm f4-5.6 LD is also available in Nikon F (FX) , Sony Alpha and Pentax KAF mounts.
Sigma 70-300mm F4-5.6 DG OS is also available in Nikon F (FX) , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Both lenses have the same focal range of 70-300mm and the fastest aperture of F4.0 - F5.6.