A user interaction system (100, 200) for controlling a lighting system comprising a plurality of controllable light sources for lighting an environment, the user interaction system (100, 200) comprising: - a display configured to display a camera image of a part of the environment, a subarea image and an overlay image, the subarea image being an image of a specific subarea of the environment, - a user input means configured to receive a user input comprising a location indication related to a point or location in the subarea image, - a location identification means (104, 204) configured to detect which specific location in the environment is indicated by the location indication, and - an overlay image creator (108, 214) configured to generate the overlay image comprising information (116, 410, 608) related to a lighting effect which is obtainable by the lighting system at the specific location, the obtainable lighting effect being a combination of lighting effects of at least two of said plurality of controllable light sources, the information (116, 410, 608) related to the obtainable lighting effect being based on a lighting system model (110, 216, 500) representing lighting effects that are obtainable in the environment by said plurality of controllable light sources, characterized in that the user interaction system (100, 200) comprises a camera configured to obtain the camera image and the subarea image, wherein the camera comprises at least one of: means for detecting a location of the camera, means for detecting a direction in which the camera is directed, a tilt sensor to detect the tilt of the camera, and means for detecting the angle of view of the camera, wherein the location identification means (104, 204) is configured to detect which specific subarea of the environment is imaged in the subarea image based on at least one of: the detected location of the camera, the detected direction of the camera, the detected tilt of the camera, and the detected angle of view of the camera, respectively, and wherein the location identification means (104, 204) is configured to base the detection of the specific location on the detected specific subarea. - a display configured to display a camera image of a part of the environment, a subarea image and an overlay image, the subarea image being an image of a specific subarea of the environment, - a user input means configured to receive a user input comprising a location indication related to a point or location in the subarea image, - a location identification means (104, 204) configured to detect which specific location in the environment is indicated by the location indication, and - an overlay image creator (108, 214) configured to generate the overlay image comprising information (116, 410, 608) related to a lighting effect which is obtainable by the lighting system at the specific location, the obtainable lighting effect being a combination of lighting effects of at least two of said plurality of controllable light sources, the information (116, 410, 608) related to the obtainable lighting effect being based on a lighting system model (110, 216, 500) representing lighting effects that are obtainable in the environment by said plurality of controllable light sources, characterized in that the user interaction system (100, 200) comprises a camera configured to obtain the camera image and the subarea image, wherein the camera comprises at least one of: means for detecting a location of the camera, means for detecting a direction in which the camera is directed, a tilt sensor to detect the tilt of the camera, and means for detecting the angle of view of the camera, wherein the location identification means (104, 204) is configured to detect which specific subarea of the environment is imaged in the subarea image based on at least one of: the detected location of the camera, the detected direction of the camera, the detected tilt of the camera, and the detected angle of view of the camera, respectively, and wherein the location identification means (104, 204) is configured to base the detection of the specific location on the detected specific subarea.