The dudes at the YouTube channel "The Slow Mo Guys" have made a pretty interesting and insightful video about shutter speeds in their usual 10,000 FPS Slow-mo. Using a DSLR, they demonstrate at super slow speeds, how a rolling shutter captures it's images at varying shutter speeds. The faster the shutter speed, the smaller the gap between the rolling shutters - pretty interesting fact I didn't know.
He also mentions how the sensor gets exposed to light (sequentially from the top of the sensor to the bottom) and how that effects your shot. Definitely worth a watch for Photographers and gear geeks.