The Panasonic Lumix G 25mm f/1.7 for Micro Four Thirds is the equivalent of the 50mm f/1.8 or f/1.7 lenses that for decades were considered the standard lenses for 35mm film cameras. Typically these were high quality optics, made in vast numbers so at relatively low cost.
High levels of sharpness; Low distortion; Low CA; Close focusing; Well made
No weather resistance; Flare levels high against the light