The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus ED 12-50mm f3.5-6.3 EZ and the Olympus M 25mm F1.8 for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Olympus ED 12-50mm f3.5-6.3 EZ is the longer of the two lenses at 83mm. The Olympus M 25mm F1.8 with a length of 41mm, is 42mm shorter. Besides being longer, the Olympus ED 12-50mm f3.5-6.3 EZ also has a larger diameter of 57mm compared to the Olympus M 25mm F1.8's 56mm diameter.
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 25mm F1.8 weighs 136g, 35% (75g) lighter than the Olympus ED 12-50mm f3.5-6.3 EZ's weight of 211g.
Filter Threads
The Olympus ED 12-50mm f3.5-6.3 EZ has a filter size of 52mm whereas the Olympus M 25mm F1.8 has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Olympus ED 12-50mm f3.5-6.3 EZ:
And these are the 46mm filters that we recommend for the Olympus M 25mm F1.8:
Lens Mounts
Both the Olympus ED 12-50mm f3.5-6.3 EZ 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-3 Astro, OM System OM-5 II and OM System OM-3.
Focal Range
Olympus ED 12-50mm f3.5-6.3 EZ has a focal range of 12-50mm and
4.2X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
24-100mm when used on a FourThirds format camera.
On the other hand, the 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.