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In the last years, multi chip on board LEDs [1, 2]became state-of-the-art to generate low beam and high beam systems.These systems often consist of one light source and one siugle optics system.On top, recent LED development enabled multi chip SMT LEDs in these systems.Alternative approaches use an assembly of several chip size SMT LEDs [3, 4] to create a single light source.The latter method offers the possibility to create light sources more flexibly than with fixed multi chip devices.In these compound light sources the single LEDs are placed close together.The compound light sources can draw upon existing optical concepts usually used with multi chip LEDs to accomplish low beam and high beam function with a single optical system.Beside differences of processing of aforementioned systems also differences in the optics design need to be considered.Due to the different structure of the multi chip and the compound light source optical differences already occur on light source level.On one hand side, the mean luminance of both light source types is different.This will be evaluated theoretically, by simulation and confirmed by exemplary measurement.On the other hand, due to the dark gaps between the individual LEDs of the compound light source, higher efforts are necessary to achieve homogeneous luminous intensity distribution.This leads typically to smaller luminous intensities that can be compensated for if the size of the optical system is enlarged compared to a system with multi chip LED light source.This dependence of luminous intensity and size of the optical system in connection with the different light source types is analyzed in detail.Theoretical considerations and simulation results will show the impact on size and performance of a headlamp system if a compound light source or a multi chip LED is used.(Abstract)