Getting back to the OP, the light intensities are way too high for Gc and IDL.  Dropping the values down to approximately 80% should begin to bring the image to what is expected.  You could even bring those values down further.  Gc will brighten the render, making it unnecessary to use many lights and high intensities.  With IDL, most of your ambient light is coming from the skydome, again you do not need to create additional lights or use higher illumination.