The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus M 17mm f1.8 and the Sigma 19mm F2.8 DN 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. Olympus M 17mm f1.8 weighs 120g, which means it is 20g (14%) lighter than the Sigma 19mm F2.8 DN which has a 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 Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both the Olympus M 17mm f1.8 and the Sigma 19mm 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-1 II, Panasonic G9 II and OM System OM-5.
Sigma 19mm F2.8 DN is also available in Sony E mount.
Focal Range
Olympus M 17mm f1.8 is a prime lens with fixed focal lenght of 17mm which has an effective (full-frame 35mm equivalent) focal range of
34mm when used on a FourThirds format camera.
On the other hand, the Sigma 19mm F2.8 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.