The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus 25mm F1.2 Pro and the Panasonic 20mm F1.7 ASPH for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Olympus 25mm F1.2 Pro is the longer of the two lenses at 87mm. The Panasonic 20mm F1.7 ASPH with a length of 26mm is 61mm shorter. Besides being longer, the Olympus 25mm F1.2 Pro also has a larger diameter of 70mm compared to Panasonic 20mm F1.7 ASPH's 63mm 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. Panasonic 20mm F1.7 ASPH weighs 100g, 75% (310g) lighter than the Olympus 25mm F1.2 Pro's weight of 410g.
Both Olympus 25mm F1.2 Pro and 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 OM System OM-5, Panasonic GH6 and OM System OM-1.
Olympus 25mm F1.2 Pro 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. 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.