You asked
Olympus pen e pm2 vs olympus om d e m5?
Both cameras share the same 16.1-megapixel Micro Four Thirds sensor and were announced in 2012, so image quality is essentially a wash. The choice comes down to handling.
The Olympus OM-D E-M5 is the one I'd pick for most people. It's weather sealed, has five-axis stabilisation in the body, and is built for hands-on shooting. The Olympus PEN E-PM2 is the smallest PEN, with few controls. That suits a pocket-sized carry-everywhere body, but you'll give up the E-M5's weather sealing and more direct controls.
Either way, a lens like the Olympus M.Zuiko 25mm f/1.8 frames like a 50mm on full frame and works on both. For sensor background, see sensor sizes.
Written by Claude from this site's pages.