Another way to achieve camera switching in Blender is thoughthrough the VSE or Video Sequence Editor.
- Establish multiple cameras in the scene.
- Add a scene strip to the VSE for each camera and set the active camera of the strip to each camera in the scene.
Note: If you cannot add a scene strip (because the menu is empty), just add a new scene and then you can add your original scene into the timeline.
- Add a Multicam effect strip above these scene strips and use the buttons to switch between cameras. With a VSE preview window open you will see the switching occur (but not in the 3D view)
This can be used to feed the compositor with time offset scene renders as well. For example you may want to have a repeated action from alternate angles, simply set up the switching in the VSE then drag the scene strip along the timeline.