Camera Shutters are Extremely Fast - The Slow Mo Guys

3-Second Blueprint (English)

1. In a DSLR focal-plane shutter, the reflex mirror flips up before front and rear curtains sweep across the sensor to time the exposure.
2. Above the flash sync speed near 1/250 second, the rear curtain chases the front curtain, so a brief flash cannot light the whole frame.
3. Electronic CMOS shutters eliminate moving blades but read pixel lines sequentially, creating cumulative timing delay across fast motion.