Freezing motion when working in the studio can be a bit confusing. Generally (say when we shoot sports) we rely on our shutter speed to freeze action. Understanding how flash duration freezes motion can clear up some misconceptions about relying on shutter speed to freeze motion. Mark Wallace does a great job explaining how older flash technology can have a tough time keeping up with the new kids in terms of short flash duration. Even if you don’t want to know about the T1 versus T5 light roll-off values, this video can offer some great information.