The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 28mm F1.4 DG HSM A and the Sigma 30mm F1.4 DC HSM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 28mm F1.4 DG HSM A is the longer of the two lenses at 108mm. The Sigma 30mm F1.4 DC HSM with a length of 63mm is 45mm shorter. Besides being longer, the Sigma 28mm F1.4 DG HSM A also has a larger diameter of 83mm compared to Sigma 30mm F1.4 DC HSM's 74mm diameter.
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.
Lens Mounts
Both Sigma 28mm F1.4 DG HSM A has the Nikon F (FX) lens mount whereas the Sigma 30mm F1.4 DC HSM has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 28mm F1.4 DG HSM A is also available in Canon EF , Sigma SA, Sony E and Leica L mounts.
Sigma 30mm F1.4 DC HSM is also available in Canon EF and Sigma SA mounts.
Focal Range
Sigma 28mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 28mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 42mm.
Sigma 30mm F1.4 DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.