A method and a microscopy imaging apparatus for generating an optically sectioned image of a specimen are provided. The method comprises the steps of: illuminating the specimen with a modulating, spatially periodic illumination pattern; imaging said specimen on a conjugate image plane; acquiring a plurality of signals at respective positions on said image plane, each signal corresponding to the incident light intensity at that position and having an oscillatory component caused by the modulation of the illumination pattern; and measuring a characteristic of the oscillatory component of each of the signals, whereby the measured characteristics when combined in their relative positions generate an optically sectioned image of the specimen.