Sometimes f/1.4 Requires 1/8000

If using an f/1.4 aperture with ISO 100 under bright sunlight, expect to need a 1/8000 shutter speed and if bright whites are in the frame, 1/8000 second may not be short enough.
 
Alternatives to (or in addition to) the 1/8000 shutter speed are neutral density filters and, if made available by the camera, ISO 50.