The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 19mm F2.8 EX DN and the Panasonic 20mm F1.7 ASPH 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 19mm F2.8 EX DN is the longer of the two lenses at 46mm. The Panasonic 20mm F1.7 ASPH with a length of 26mm, is 20mm shorter. On the other hand, the Panasonic 20mm F1.7 ASPH has a larger diameter of 63mm compared to the Sigma 19mm F2.8 EX DN's 61mm 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. Panasonic 20mm F1.7 ASPH weighs 100g, 28% (40g) lighter than the Sigma 19mm F2.8 EX DN's weight of 140g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Wideangle Prime Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both the Sigma 19mm F2.8 EX DN and the Panasonic 20mm F1.7 ASPH has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are , and .
Sigma 19mm F2.8 EX DN is also available in Sony E mount.
Focal Range
Sigma 19mm F2.8 EX DN is a prime lens with fixed focal lenght of 19mm which has an effective (full-frame 35mm equivalent) focal range of 28.5mm when used on a APS-C / DX format camera. Panasonic 20mm F1.7 ASPH 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.