Max Shutter speed
Olympus E-M1 can shoot continuously at max speed of
10 fps and has max shutter speed of
1/8000 sec.
Flash
Unfortunately E-M1 doesn't have a built-in flash but it has a flash shoe for mounting external flashes.
Focusing
Olympus E-M1 features both Contrast Detection and Phase Detection autofocus (AF) systems which ensures speed and accuracy of focusing in most situations. The AF system has 81 points to choose from. Olympus E-M1 also features
Face detection AF where it intelligently detects the faces in the frame and locks the focus automatically.
Focus Stacking
Macro shooters will love Olympus E-M1's Focus Stacking feature. In this mode, E-M1 automatically composites multiple shots taken at different focal positions using focus bracketing to create a single image with maximum depth of field.