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 Olympus 25mm F1.2 Pro 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 OM ED 20mm F1.4 Pro with a length of 62mm is 25mm shorter. Besides being longer, the Olympus 25mm F1.2 Pro also has a larger diameter of 70mm compared to OM ED 20mm F1.4 Pro'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. OM ED 20mm F1.4 Pro weighs 247g, which means it is 163g (39%) lighter than the Olympus 25mm F1.2 Pro which has a weight of 410g.
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
Lens Mounts
Both OM ED 20mm F1.4 Pro and Olympus 25mm F1.2 Pro 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.
Focal Range
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. 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.