The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 56mm F1.4 DC DN C and the Sigma 120-400mm F4.5-5.6 DG 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 120-400mm F4.5-5.6 DG HSM is the longer of the two lenses at 203mm. The Sigma 56mm F1.4 DC DN C with a length of 60mm, is 143mm shorter. Besides being longer, the Sigma 120-400mm F4.5-5.6 DG HSM also has a larger diameter of 92mm compared to the Sigma 56mm F1.4 DC DN C's 67mm 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 56mm F1.4 DC DN C weighs 280g, which means it is 1360g (82%) lighter than the Sigma 120-400mm F4.5-5.6 DG HSM which has a weight of 1640g.
Filter Threads
The Sigma 56mm F1.4 DC DN C has a filter size of 55mm whereas the Sigma 120-400mm F4.5-5.6 DG HSM has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Sigma 56mm F1.4 DC DN C:
And these are the 77mm filters that we recommend for the Sigma 120-400mm F4.5-5.6 DG HSM:
Lens Mounts
The Sigma 56mm F1.4 DC DN C has the Sony E lens mount whereas the Sigma 120-400mm F4.5-5.6 DG HSM has the Sony Alpha lens mount. Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Sony A99 II, Sony A68 and Sony A77 II for the Sony Alpha Mount.
Sigma 56mm F1.4 DC DN C is also available in the Micro Four Thirds and Leica L mounts.
Sigma 120-400mm F4.5-5.6 DG HSM is also available in Pentax KAF3 mount.
Focal Range
Sigma 56mm F1.4 DC DN C is a prime lens with fixed focal lenght of 56mm which has an effective (full-frame 35mm equivalent) focal range of
84mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 120-400mm F4.5-5.6 DG HSM has a focal range of 120-400mm and 3.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 180 - 600mm.
