Method and system for real time correction of an image

The present invention relates to a system and method for real time correction of light output and/or colour of an image displayed on a display device. The system comprises:a display device comprising an active display area for displaying the image, an image forming device and an electronic driving system for driving the image forming device, an optical sensor unit comprising an optical aperture and a light sensor having an optical axis, to make optical measurements on a light output from a representative part of the active display area of the image forming device and generating optical measurement signals therefrom, a feedback system receiving the optical measurement signals and on the basis thereof controlling the electronic driving system. The optical aperture of the optical sensor unit has an acceptance angle such that at least 50%, alternatively 60%, alternatively 70%, alternatively 75% of the light received by the sensor comes from light travelling within 15° of the optical axis of the light sensor.