Question

Why is movement difficult to catch on a camera?

Answer 1

A camera works by opening its shutter to expose the light sensitive material beneath it (traditionally film has been used. I’m not sure what digital cameras use to capture pictures). The light reflected off objects stream into the camera and leave an impression. If something is moving, the light is moving with it. The longer the shutter is open, the more the light blurs as the object moves. If you want to capture movement, I recommend a quick shutter speed

Answer 2

Because of the time it takes for the light to transfer from the object to the camera sensor, which isn't all that fast.