In answer to another questionanother question, Adam Davis writes:
Your camera complicates this by using a rolling shutter above a given speed (usually around 1/200. This means that only a portion of the image sensor is exposed to the scene at any given time, so if the light changes during the exposure, the color change will only affect a portion of the image sensor.
Rolling shutters often are also mentioned in the context of DSLR videographycontext of DSLR videography. However, I am yet to see a discussion of what a rolling shutter is, how it works and when it is important.
What is a rolling shutter?
What are the implications of using one for my photos?