Fluorescence

The Point-Spread FunctionFor this reversal the „point-spread-function“(PSF) is either calculated or experimentallydetermined and the PSF is the basis for thismathematic reversal approach.The point spread function is the image of apoint source of light from the specimenprojected by the microscope objective ontothe intermediate image plane, i.e. the pointspread function is represented by the Airydisk pattern (see resolution). Due todiffraction, the smallest point to which onecan focus a beam of light using a lens is thesize of the Airy disk. PSF of a system is thethree dimensional diffraction patterngenerated by an ideal point source of light.The PSF is a measure for the ability of asystem to create contrast for a givenresolution in the intermediate image plane.PSF of an individual objective or a lenssystem depends on numerical aperture,objective design, illumination wavelength,and the contrast mode.http://www.biomedical-engineering-online.com/content/5/1/36