How even is the color and intensity across the arc (the light source)?
The ends of the arc has almost double the intensity and bluest color. Which means that optical engineers can make headlamp output bluer (or more yellow) than the bulb output color is, without using color filters (like they do in photograpy). For HID retrofitting in halogen headlamps, this a feature that cannot be utilized. Its pretty obvious that a chromed reflector cannot be reshaped in any way. So a unlucky retrofitter CAN end up with color spectrum from brown to bright white – in different places of the beam.
