An apparatus and method for depth selected fluorescence measurements is provided. The apparatus may include a carrier for at least one sample substance; projection optics; an image capture module; a signal processor to transform the data image to provide depth selected fluorescence measurement for the at least one sample substance. The apparatus is arranged such that a first optical axis is inclined relative to a second optical axis so that the projection optics have an angle of inclination relative to the image plane. The angle of inclination is selected so that a component of excitation radiation incident upon, but not absorbed by, the at least one sample substance is scattered or reflected to reduce excitation radiation from reaching the detection beam path.