The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 50mm F1.8 and the Sigma 56mm F1.4 DC DN C for their suitability to various photography scenarios:
Size and Weight Comparison
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. Sony FE 50mm F1.8 weighs 186g, which means it is 94g (33%) lighter than the Sigma 56mm F1.4 DC DN C which has a weight of 280g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Sony E Mount for size comparison purposes.
Standard Lenses in Sony E Mount for Size Comparison
Filter Threads
The Sony FE 50mm F1.8 has a filter size of 49mm whereas the Sigma 56mm F1.4 DC DN C has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Sony FE 50mm F1.8:
And these are the 55mm filters that we recommend for the Sigma 56mm F1.4 DC DN C:
Lens Mounts
Both the Sony FE 50mm F1.8 and the Sigma 56mm F1.4 DC DN C has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A9 III, Sony A7C Mark II and Sony A7CR.
Sigma 56mm F1.4 DC DN C is also available in Micro Four Thirds and Leica L mounts.
Focal Range
Sony FE 50mm F1.8 is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the 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.