Hi Everyone - With @matthewepler’s help on some quarantine 3D printing I tested a model based on the Right-Angle Diffuser Box design:
(shown here as two halves for printing purposes)
Two versions of this were made, one printed with White PLA and one with Black PLA. I tested the White PLA model without any extra coating, and then both models after applying the same Barium Sulfate/Latex paint diffuse reflective coating that I used in testing the earlier designs in this thread. I performed the same measurements on these variations using the same White LED and driver from the earlier tests. These are the results:
The RA Diffuser Box model generally underperforms the Integration Sphere in both measured falloff and illuminance, however it is notably better than the earlier Direct Drive model. The uncoated White PLA performs quite poorly compared to the coated PLA.
I believe the falloff observed in this model is mainly the result of the LED being aimed directly at the “45 degree” diffuse reflector and causing a hot spot on the part of the reflector closest to the LED. Also the length of the tube between the reflector and the aperture likely caused some of the measured falloff. The next iteration of this design will place the LED such that the light will have to perform at least one bounce before reaching the final reflective surface as well as a shorter distance from the final reflective surface and the aperture.