An apparatus is disclosed for depth selected fluorescence measurements of a sample. The apparatus may include a carrier for at least one sample substance, the carrier having at least one transparent, planar bottom wall having an upper surface; projection optics having a first optical axis, to expose the at least one sample substance through the bottom wall to a spatially structured pattern of excitation radiation, the projection optics including a first object plane and an image plane that are subject to a Scheimpflug condition, the image plane being substantially coplanar with the upper surface of the bottom wall of the carrier; an image capture module having a second optical axis, a second object plane substantially coplanar with the image plane, and a detection beam path, to receive a data image from the sample; a signal processor to transform the data image to provide depth selected fluorescence measurement for the at least one sample substance; and an arrangement whereby the first optical axis is inclined relative to the second optical axis so that the projection optics has an angle of inclination relative to the image plane, the angle of inclination being selected such that a component of excitation radiation incident upon, but not absorbed by, the at least one sample substance is scattered or reflected to substantially reduce excitation radiation from reaching the detection beam path. A corresponding method is disclosed.