The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic 20mm F1.7 ASPH and the Olympus M 25mm F1.8 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. Olympus M 25mm F1.8 is the longer of the two lenses at 41mm. The Panasonic 20mm F1.7 ASPH with a length of 26mm, is 15mm shorter. On the other hand, the Panasonic 20mm F1.7 ASPH has a larger diameter of 63mm compared to the Olympus M 25mm F1.8's 56mm 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, which means it is 36g (26%) lighter than the Olympus M 25mm F1.8 which has a weight of 136g.
Both the Panasonic 20mm F1.7 ASPH and the Olympus M 25mm F1.8 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.
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. Olympus M 25mm F1.8 is a prime lens with fixed focal lenght of 25mm which has an effective (full-frame 35mm equivalent) focal range of 50mm when used on a FourThirds format camera.