Camera Shutter

Notes from Cyrill Stachniss.

Shutter speed controls how much light you are letting in.

Rolling shutter

  • The shutter rolls (moves) across the exposable image area
  • The pixels at the same line of the image are recorded at the same time § Produces distortions in case of fast-moving objects or cameras
  • Often found in CMOS cameras

Why are rolling shutters used?

Because they’re very CHEAP.

Rolling shutters read one line after the other.

  • This is kind of how a LiDAR works!

Are most cameras rolling shutters?

It depends. Many DSLR and mirrorless cameras use a mechanical focal-plane shutter, which is not the same as a rolling shutter.

You actually need to take this into account.

The other one is a global shutter

  • The whole image is recorded at exactly the same time
  • No rolling shutter distortions
  • Preferable for geometric reconstruction task

More expensive to produce, so we don’t find them as often.