Originally Posted by sarathmenon
You did not mention this, but is this setup road legal? Typically, what I've heard is that HID and LEDs emit their light in a different way from incandescent lights, which is why they require different ballasts. And because of this property, it's supposedly difficult to imitate the light pattern of incandescent using the LED arrays.
Don't get me wrong. You sell lights for a living, and you know this shit better than I do. I've had plenty of moments when a schmuck in the opposite lane has one of these cheap ebay kits. The light is blinding in my side and I can clearly see that there is hardly any lumination on their side of the road. And they invariably sport the wrong version of white.
The ballast is a power supply of sorts. It converts the 13.8V DC into something the bulb can use. The light output has nothing to do with the ballast.
HID's are intended for use in Projector housings. If you're being blinded by another driver's headlights, it's because they have HID's in a standard reflector housing because they're too dumb, lazy, or just don't care to put projectors in their headlights. There is very little gain by having HID's in a reflector housing over a standard halogen bulb. (Especially in the fog! The scatter makes it terrible!) The real improvement is anytime you introduce a projector. The lens controls the light output and makes it even and keeps it out of other drivers eyes.
Look into projector headlights and how they work. A good source is Theretrofitsource.com (I'm not affiliated, just a happy customer) and the HIDPLANET website.
Also, ebay pre-made projector housings are about as useful as a broken contraceptive device.