A method for the optical determination of an intensity distribution, includes a) producing a spatially inhomogeneous radiation field of electromagnetic radiation; b) producing a first relative movement between a position-resolving image sensor and the radiation source with the radiation field moving along a first measurement path over a sensor field of the image sensor, so it is scanned by a first measurement path region of the radiation field; c) recording a first image set with position-resolved images of the radiation field during the first movement; d) producing a similar second relative movement between the image sensor and the radiation source, along a second measurement path not parallel to the first movement path; d) similarly recording a second image set during the second relative movement; e) evaluating the position-resolved images of the first and second image sets at least at points of intersection, the locations of which are defined by evaluation lines; and f) determining a relative intensity distribution based on points of intersection of the evaluation lines to characterize the image sensor and/or the radiation field.