An apparatus and an associated method determine the fiber orientation of a moving fibrous web, in particular a paper, cardboard or cellulose web. An illumination device illuminates an area of the fibrous web and a camera records a digital image of the illuminated area of the fibrous web. The illumination device is configured to illuminate the fibrous web for a period of time of 1 μs or less and the camera is configured in such a way that the edge length of a pixel corresponds to no more than 20 μm, in particular no more than 10 μm.

An LED matrix lighting device for illuminating a lighting pattern with even intensity. The LED matrix lighting device includes a plurality of LEDs, a collimating lens in front of each LED for collimating light of the LED, and a light refracting element in front of collimating lenses arranged to refract light of at least a first part of the LEDs with a different refraction angle than at least a second part of the LEDs. The disclosure further relates to a machine vision system, a method, and a computer program product.

An apparatus and an associated method determine the fiber orientation of a moving fibrous web, in particular a paper, cardboard or cellulose web. An illumination device illuminates an area of the fibrous web and a camera records a digital image of the illuminated area of the fibrous web. The illumination device is configured to illuminate the fibrous web for a period of time of 1 s or less and the camera is configured in such a way that the edge length of a pixel corresponds to no more than 20 m, in particular no more than 10 m.