Focal Plane Shutter VS Leaf Shutter

Ever wondered what difference a Leaf Shutter makes? The following article by Brad Kaye gives a good overview:

The two images below from his article demonstrate the difference in how the two work.

Without the leaf shutter involved, the fastest shutter speed you can use and still sync a strobed flash into is limited by the last time value the focal plane shutter is entirely open all at one time.  Faster than that, the focal plane curtains chase each other thru the frame, with the digital sensor (or film)never having the opportunity to see the entire frame open at once.
This motion allows for fast sync speeds with very little light falloff, allowing you to shave ambient exposure out of your scene, whether it’s the ambient/modeling lights in your studio, unwanted objects on location, or simply to shape light in a way outdoors mid-day that isn’t wholly dependent on the sun.