The invention relates to a light emitter adapted for emitting light with a predefined angular color point distribution, to a method of use for a light emitter in video flash applications, in automotive headlight applications andor in automotive lamp applications, and to a method, adapted for generating light with a predefined angular color point distribution. In this way a direct one-to-one link is obtained between a set of shim currents and the associated NMR spectrum The quality of the desired NMR spectra can be improved with this method. The lift screen is possible to be set up into multiple forms with multiple functions so as to offer a high mobility and more flexibility while in use and to be set up into a form with a worktable, so as to satisfy various needs and desired arrangements.