Viewfinder and stray light

When shooting with an EOS camera, especially if the camera is on a tripod, you should always aim to reduce stray light entering the camera through the viewfinder. If you are shooting in a semi-automatic mode like P, Tv or Av, stray light may affect the exposure metering resulting in images that are usually too dark. It’s for this reason that EOS cameras are supplied with an eyepiece cover. However, if you are in a rush then simply holding your hand in front of the viewfinder to mimic your eye being there is usually sufficient. If you are shooting in Manual with a manually set ISO, then you shouldn’t need to worry as the exposure cannot be changed automatically before the shot is taken.
Camera settings