The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 40mm F1.4 DG HSM A and the Sigma 50mm F1.4 DG HSM A for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 40mm F1.4 DG HSM A is the longer of the two lenses at 131mm. The Sigma 50mm F1.4 DG HSM A with a length of 100mm, is 31mm shorter. Besides being longer, the Sigma 40mm F1.4 DG HSM A also has a larger diameter of 88mm compared to the Sigma 50mm F1.4 DG HSM A's 85mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods.
Below you can find the dimension and weight table of the Standard Prime Lenses in Sigma SA Mount for size comparison purposes.
Standard Prime Lenses in Sigma SA Mount for Size Comparison
Lens Mounts
Both the Sigma 40mm F1.4 DG HSM A and the Sigma 50mm 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 40mm F1.4 DG HSM A is also available in Canon EF , Nikon F (FX), Sony E and Leica L mounts.
Sigma 50mm F1.4 DG HSM A is also available in Canon EF , Sony Alpha, Nikon F (FX) and Leica L mounts.
Focal Range
Sigma 40mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 40mm. Sigma 50mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 50mm.