So i'm after a lens for my Olympus EM-10 for street shooting. But i'm on a budget. The three lenses i've seen and heard good and bad points about are: Oly 17mm f2.8 Pany 14mm f2.4 Pany 20mm f1.7 II The first two are about the same price as far as i can see, the Pany 20mm will be about £70-£80 more. Anyone own either of these lenses and can give there 2 cents? Is 14mm too wide? Is 20mm too long? Is the 20mm slow at focusing? Is the 17mm not as sharp?