1. A device for radiometrically measuring a surface of a measurement object (O) that includes effect pigments or flakes embedded in a substrate material, comprising: at least one measurement array ( 100 ; 200 ; 300 ; 400 ) featuring an illumination array ( 110 ; 210 ; 410 ) and a pick-up array ( 120 ; 220 ; 420 ); a processor (P) configured to control the illumination array ( 110 ; 210 ; 410 ) and the pick-up array ( 120 ; 220 ; 420 ) and to process measurement signals produced by the pick-up array ( 120 ; 220 ; 420 ) and to provide processed image data, and firmware accessible by the processor and in which a plurality of point spread function (PSF) correction parameters are stored, each PSF correction parameter being derived from a corrected device-independent point spread function corresponding to one of a plurality of color channels; wherein the illumination array ( 110 ; 210 ; 410 ) comprises at least one light source ( 111 ) and is configured to expose a region of the measurement object (O) to illumination light at an illumination angle (θ i ) and an illumination aperture angle (α i ), wherein the pick-up array ( 120 ; 220 ; 420 ) comprises a photoelectric image sensor ( 122 ) and is configured to capture measurement light, reflected by the measurement object (O), at a pick-up angle (θ v ) and a pick-up aperture angle (α v ) and to direct it onto the image sensor ( 122 ), wherein the illumination array ( 110 ; 210 ; 410 ) is configured to produce illumination light in multiple spectral ranges and/or the pick-up array ( 120 ; 220 ; 420 ) is configured to split captured measurement light into multiple spectral ranges, such that the image sensor ( 122 ) produces multispectral image data corresponding to the plurality of color channels, wherein illumination aperture angle (α i ) of the illumination array ( 110 ) and/or the pick-up aperture angle (α v ) of the pick-up array ( 120 ) is/are greater than the angular variation caused by the material dispersion over the spectral measurement range of the light reflected by an effect pigment or flake embedded in the substrate material; and wherein the processed image data is derived from the multispectral image data processed with respective PSF correction parameters.