When the Camera property is clicked a down arrow appears to access a drop down menu of cameras in the project. The Camera drop-down list will show the selected photograph(s)' Camera. To change the photograph(s) so it uses a different camera, press the down arrow and pick a new camera. If the Camera does not appear it means it is not loaded into the project. In this case press the “Open project cameras” hyperlink to bring up the Camera Viewer Dialog. This dialog will allow you to load, save, create and modify Cameras. On reassigning a camera and hitting OK on the dialog in some cases you may see the Image Check Dialog which indicates that a camera and photo do not match.