Abstract: A sensor system for determining an optical property of a plant by means of a reflection measurement, having a first light source, which emits light along a first beam axis, and a second light source, which emits light along a second beam axis, and at least one receiver, which is aligned along a third beam axis, to detect light reflected from the plant. The first light source, the second light source, and the receiver are arranged relative to one another so that a target cylinder, which respectively extends along the first beam axis and the second beam axis, and a first measuring cylinder, which extends along the third beam axis, at least partially overlap one another in a measuring space, and the first beam axis and the second beam axis respectively enclose an angle (?, ?) with the third beam axis. Related methods are also disclosed.