A device for determining properties of surfaces having at least one first radiation device having at least one radiation source emitting radiation, having at least one first radiation detector having a first radiation detector element which captures at least a portion of the radiation emitted from the radiation device and subsequently diffused and/or reflected off a measuring surface and emits at least one measuring signal characteristic of the reflected/diffused radiation, and at least one second radiation detector having a second radiation detector element capturing a portion of the radiation from the radiation device and diffused/reflected off a measuring surface and outputs a measuring signal characteristic of the reflected and/or diffused radiation, and at least one filter device which is placeable both in the optical path between the radiation device and the first radiation detector and in the optical path between the radiation device and the second radiation detector.