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 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. Sigma 70-300mm F4-5.6 DG is the longer of the two lenses at 122mm. The Tamron AF 70-300mm f4-5.6 LD with a length of 117mm, is 5mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 77mm.
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 AF 70-300mm f4-5.6 LD weighs 435g, which means it is 115g (20%) lighter than the Sigma 70-300mm F4-5.6 DG which has a weight of 550g.
Below you can find the dimension and weight table of the Telephoto Zoom Lenses in Pentax KAF Mount for size comparison purposes.
Telephoto Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
The Tamron AF 70-300mm f4-5.6 LD has a filter size of 62mm whereas the Sigma 70-300mm F4-5.6 DG has a 58mm 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 AF 70-300mm f4-5.6 LD:
And these are the 58mm filters that we recommend for the Sigma 70-300mm F4-5.6 DG:
Lens Mounts
Both the Tamron AF 70-300mm f4-5.6 LD and the Sigma 70-300mm F4-5.6 DG has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Tamron AF 70-300mm f4-5.6 LD is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Sigma 70-300mm F4-5.6 DG is also available in Canon EF , Nikon F (FX), Pentax KAF, Sony Alpha, Sigma SA, Canon EF, Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
Both lenses have the same focal range of
70-300mm and the fastest aperture of
F4.0 - F5.6.