You asked
Is the olympus m zuiko 25mm f 1 8 worth it?
Yes, if you shoot Micro Four Thirds and want one natural, everyday lens. On that sensor the 25mm f/1.8 frames like a 50mm on full frame, which is a comfortable view for street, travel, and general walking-around shooting. Its f/1.8 aperture gives you about the depth of field of f/3.6 there, so you get some background separation without much fuss. It autofocuses but isn't stabilised, so you'll rely on your camera body for that.
It fits a long list of bodies, including the OM System OM-1 and OM System OM-5. If you want more light and shallower depth of field, the Olympus M.Zuiko 25mm f/1.2 PRO is the step up. For people, the portrait lens guide explains where this focal length fits in.
Written by Claude from this site's pages.