Continuing the discussion from Cotty's gallery images:
To start with, these points are very important:
- model as accurate as possible (to scale, with all relevant details like active emitting areas, lenses, …)
- use adequate materials
- instead of modeling the LED, you can try to create a IES light with the desired lightning pattern
Since V-Ray is a physically based raytracer, it is possible to get very realistic results with the right setup.
Do you have an example of the current result and the ideal goal?