The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 300mm F2.8 APO EX DG HSM and the Sigma 120-300mm F2.8 DG 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. Sigma 120-300mm F2.8 DG OS HSM is the longer of the two lenses at 291mm. The Sigma 300mm F2.8 APO EX DG HSM with a length of 215mm, is 76mm shorter. Besides being longer, the Sigma 120-300mm F2.8 DG OS HSM also has a larger diameter of 124mm compared to the Sigma 300mm F2.8 APO EX DG HSM's 119mm 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. Sigma 300mm F2.8 APO EX DG HSM weighs 2400g, which means it is 550g (18%) lighter than the Sigma 120-300mm F2.8 DG OS HSM which has a weight of 2950g.
Filter Threads
The Sigma 300mm F2.8 APO EX DG HSM has a filter size of 46mm whereas the Sigma 120-300mm F2.8 DG OS HSM has a 105mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 46mm filters that we recommend you to consider for the Sigma 300mm F2.8 APO EX DG HSM:
And these are the 105mm filters that we recommend for the Sigma 120-300mm F2.8 DG OS HSM:
Lens Mounts
The Sigma 300mm F2.8 APO EX DG HSM has the Sigma SA lens mount whereas the Sigma 120-300mm F2.8 DG OS HSM has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill for the Sigma SA Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 300mm F2.8 APO EX DG HSM is also available in the Canon EF , Nikon F (FX), Pentax KAF and Sony Alpha mounts.
Sigma 120-300mm F2.8 DG OS HSM is also available in Canon EF and Sigma SA mounts.
Focal Range
Sigma 300mm F2.8 APO EX DG HSM is a prime lens with fixed focal lenght of 300mm.
On the other hand, the Sigma 120-300mm F2.8 DG OS HSM has a focal range of 120-300mm and 2.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 180 - 450mm.
