The type of photography that you are planning to use is an important decision factor. Here we have evaluated the OM ED 20mm F1.4 Pro and the Sigma 30mm F2.8 DN for their suitability to various photography scenarios:
Size and Weight Comparison
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. Sigma 30mm F2.8 DN weighs 135g, 45% (112g) lighter than the OM ED 20mm F1.4 Pro's weight of 247g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Standard Prime Lenses in Micro Four Thirds Mount for Size Comparison
Both the OM ED 20mm F1.4 Pro and the Sigma 30mm F2.8 DN has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-5, Panasonic GH6 and OM System OM-1.
Sigma 30mm F2.8 DN is also available in Sony E mount.
OM ED 20mm F1.4 Pro is a prime lens with fixed focal lenght of 20mm which has an effective (full-frame 35mm equivalent) focal range of 40mm when used on a FourThirds format camera. Sigma 30mm F2.8 DN 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.