A study on selecting of Light Cutoff Panel depending on the installation condition using the lighting simulation

The use of security lighting that emits spill light is considered a cause of light trespass problems in the residential areas. Therefore, a cutoff panel was installed as an alternative way to reduce light trespass. On the other hand, it has another problem in that it is less effective and is not good enough for aesthetics and safety. In this study, a light cutoff panel was designed and manufactured to reduce the light trespass, and the structure of a proper light cutoff panel was studied. Using a goniophotometer, the light distribution file (IES file) was extracted and the characteristics of light distribution were analyzed using the RELUX program. The results showed that the reduction of spilt light in the backward direction was decreased significantly for all types of light cutoff panels except the coated globe. In the case of a black powder coated light cutoff panel, the forward light caused by light reflected from the surface of the light cutoff panel was also reduced, which means that the black powder coated light cutoff panel is effective in the performance of light cutoff in the forward and backward directions. In addition, the coated glove increased the spilt light in the forward and backward directions because it reflects the upward light to go down. A 90 % accuracy between the measurement value of light trespass and the expected value of the light trespass was obtained from a simulation.