 This way a thin sheet of light or lightsheet is created in the focal region that can be used to excite fluorescence only in a thin slice (usually a few micrometers thin) of the sample.The fluorescence light emitted from the lightsheet is then collected perpendicularly with a standard microscope objective and projected onto an imaging sensor (usually a CCD, electron multiplying CCD or CMOS camera).In order to let enough space for the excitation optics/lightsheet an observation objective with high working distance is used.