The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.8 EX DG RF and the Sigma 24mm F1.4 DG HSM A 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. Sigma 20mm F1.8 EX DG RF weighs 520g, which means it is 145g (21%) lighter than the Sigma 24mm F1.4 DG HSM A which has a weight of 665g.
Filter Threads
The Sigma 20mm F1.8 EX DG RF has a filter size of 82mm whereas the Sigma 24mm F1.4 DG HSM A 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 82mm filters that we recommend you to consider for the Sigma 20mm F1.8 EX DG RF:
And these are the 77mm filters that we recommend for the Sigma 24mm F1.4 DG HSM A:
Lens Mounts
Both the Sigma 20mm F1.8 EX DG RF and the Sigma 24mm F1.4 DG HSM A has the same Sigma SA lens mount. Some of the latest released cameras that are compatible with the Sigma SA lenses are Sigma Quattro, Sigma Quattro H and Sigma SD1 Merrill.
Sigma 20mm F1.8 EX DG RF is also available in Canon EF , Nikon F (DX), Pentax KAF and Sony Alpha mounts.
Sigma 24mm F1.4 DG HSM A is also available in Canon EF , Nikon F (FX) and Leica L mounts.
Focal Range
Sigma 20mm F1.8 EX DG RF is a prime lens with fixed focal lenght of 20mm.
On the other hand, the Sigma 24mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 24mm.