The severity of the disco effect (colored shadows) is significantly reduced by the optics.
All light (from each individual LED and color) angles >63 are coupled in the light guide. Within this light guide, all colors are mixed and re-distributed in a diffuse, broad pattern. This light is added (summed up) to the direct light (with angles <63 degree) resulting in a source with a more homogeneous colored distribution.
After various user-tests the caustic effect inside the aquarium was still considered to be too dynamic. As stated above, the caustic effect can be reduced by increasing the source size. The virtual source size may be increased by applying a diffuser in front of the source, implemented in the glass cover plate by using an abrasive blasting technique.
The cover plate abrasion is tuned to scatter the light just slightly, in order to provide an increase in source size without compromising (i) the optical efficiency, and (ii) the beam cut-off needed to suppress disturbing caustics outside of the aquarium.
Advantages CoralCare optical system:
• Drastically reduces caustic effect outside of the aquarium (>63 degree beam angle)
• Light >63 degree is captured in light guide and scattered into a broad diffuse light distribution that do not produce caustics.
• No optical loss of light <63 degree between source and target.
• Significantly improves the color mixing of LED engine (see Fig. 8)
• The lightguide increases the source size, resulting in balanced caustic effects.