A method for detecting motion in a scene using a time-of-flight sensor, wherein the time-of-flight sensor comprises at least one photo-sensitive element comprising at least a first element with a modifiable first charge level and a second element with a modifiable second charge level, the method comprising for a single exposure time of the photo-sensitive element: driving the at least one photo-sensitive element during the exposure time such that charge carriers generated in the photo-sensitive element by light received from the scene during the exposure time modify the first charge level for a first fraction of the exposure time and modify the second charge level for a second fraction of the exposure time; determining whether motion occurred in the scene during the exposure time based on a difference between the first charge level and the second charge level, wherein the scene is not illuminated by the time-of-flight sensor during the exposure time such that the light received from the scene comprises only ambient light, and wherein, if it is determined that motion occurred during the exposure time, the method further comprises for a single further exposure time of the photo-sensitive element: illuminating the scene with light; driving the at least one photo-sensitive element during the further exposure time such that charge carriers generated in the photo-sensitive element by light received from the scene during the further exposure time modify the first charge level for a first fraction of the further exposure time and modify the second charge level for a second fraction of the further exposure time; and determining whether motion occurred in the scene during the further exposure time based on a difference between the first charge level and the second charge level. driving the at least one photo-sensitive element during the exposure time such that charge carriers generated in the photo-sensitive element by light received from the scene during the exposure time modify the first charge level for a first fraction of the exposure time and modify the second charge level for a second fraction of the exposure time; determining whether motion occurred in the scene during the exposure time based on a difference between the first charge level and the second charge level, wherein the scene is not illuminated by the time-of-flight sensor during the exposure time such that the light received from the scene comprises only ambient light, and wherein, if it is determined that motion occurred during the exposure time, the method further comprises for a single further exposure time of the photo-sensitive element: illuminating the scene with light; driving the at least one photo-sensitive element during the further exposure time such that charge carriers generated in the photo-sensitive element by light received from the scene during the further exposure time modify the first charge level for a first fraction of the further exposure time and modify the second charge level for a second fraction of the further exposure time; and determining whether motion occurred in the scene during the further exposure time based on a difference between the first charge level and the second charge level. illuminating the scene with light; driving the at least one photo-sensitive element during the further exposure time such that charge carriers generated in the photo-sensitive element by light received from the scene during the further exposure time modify the first charge level for a first fraction of the further exposure time and modify the second charge level for a second fraction of the further exposure time; and determining whether motion occurred in the scene during the further exposure time based on a difference between the first charge level and the second charge level.