A mirror camera system includes a camera fixed to a top of a convertible roof of a vehicle and positioned to capture image data of a scene rear of the vehicle, and a rearview mirror with an integrated display connected to the camera. The mirror camera system is switchable between a camera mode, which shows the image data captured by the camera on the integrated display, and a standard mirror mode, which shows an environment behind the vehicle on a semitransparent reflective surface of the rearview mirror. The rearview mirror includes an electronic control unit that is configured to analyze the image data output from the camera to determine a luminance value of the scene, and further configured to send a signal to switch the mirror camera system from the camera mode to the standard mirror mode when the luminance value of the scene is within a predetermined threshold range.