see also:

• a catalogue of Micro Four Thirds lenses
• 17mm "wide angle" street photography lenses for Micro Four Thirds
• 45mm "portrait" lenses for Micro Four Thirds
• Lens Rentals testing of the MFT 25mm options

• There are a number of 25mm-30mm lenses for Micro Four Thirds system which give the full frame “50mm standard lens” field of view
• not compared below is the Olympus mZD 25mm f/1.8 ($AU430), the Sigma 30mm f/2.8 ART and Panasonic 30mm f/2.8 OIS macro ($AU399)
• in addition, there is the Four Thirds lens - the superb, expensive ($AU1799), heavy (510g+adapter), discontinued Panasonic Leica D 25mm f/1.4 which requires an adapter, has slower CDAF, close focus only 0.38m, 0.5% distortion, 1.1EV vignetting wide open, 62mm filter thread and 78mm long + adapter.
• note the DxOMark scores cannot be compared with full frame systems as different sensors and measurements are used, but a similar table for 50mm full frame lenses on hi res cameras is here, but these at f/1.4 will give you around 1.5EV shallower DOF but note that these high quality f/1.4 50mm full frame lenses are twice the weight and will only close focus down to around 0.45m - the Olympus gets down to twice as close and is much better suited to street photography given the lower weight and size!
• the Panasonic Leica DG 10-25mm f/1.7 lens MFT optical quality can match a 25mm prime lens, so should be factored in as an alternative, especially if you are a Panasonic videographer but it is heavy, large, expensive and has more field curvature than the Olympus f/1.2 lens