HID bulbs in Halogen Projector
 

I've been asked quite a few times "can I just swap my halogen bulbs for HID bulbs in my projector headlights?"
Yes and no
Yes it can be done BUT:
because a halogen projector is ment for halogen bulbs the focus is thrown off when HID bulbs are swapped in to the housing.
Here are a few photos using a mazda 3 halogen projector.
First one below is a stock halogen h11 bulb
Attachment 4902
Notice it has a nice clean cut off right around the step? (when I say step ___/--)
Now below is one of my 5000k H11 HID bulbs
Attachment 4903
If you look at the cut off area around the step you can now see that it is blurred. This is because the focus point of a halogen projector is different from HID projectors.
The reply I get is yea, so what I never get flashed it not as bad as plug and play in non projectors.
Well the blurr that is around that cut off is now glare that blinds oncoming traffic. I am sure you have seen other people running plug and play HID and have been blinded, well you are now doing the same thing.
Just in case you have a hard time with the 5000k photo
Below is a 3000k h11 bulb I also sell. I put it in the same halogen projector. This helps bring out the extra fuzzyness that the cut off now has compaired to the halogen bulb. not much of a clean cut off.
Attachment 4904
Just for reference:
below is a 5000k bulb in a HID projector designed for HIDs.
Attachment 4905

A good site: (3") Mazda 3 - Clear Lenses from The Retrofit Source Inc
I am not totally pleased with my Mazda 6 Low beams. I changed bulbs and did re-aim them, still not really satisfied but don't like reliabilty of HID lights.
Also found this pic, OE lens is opaque, TRS is clear;