The invention relates to a process and a device for detecting or recognizing an object by means of color recognition or brightness evaluation, whereby radiation emitted by a radiation source on the object and radiation reflected from the object is recorded by a photosensitive element such as a color-recognizing sensor. In order to be able to detect objects with a higher measuring exactitude, whereby changes in distance between object and light-sensitive element should not basically lead to a measurement falsification, it is suggested that reflected radiation be guided to the photosensitive element by means of a light-guiding element tapering in the direction of the photosensitive element.