I'm not sure if i understand wat u tryin to say here but i think u want to fit a H4 HiD bulb into a H4 halogen housing and in the process achieving glare less halogen cutoff!
If this is the case than u need to understand 1 thing that halogen lights are supposed to glare other wise they will be too dim to be noticed. Thats the design principle for a halogen headlight. Things become ugly when someone puts a HiD bulb in a Halogen headlight and while staring at the SUN(headlight) assumes that they have achieved more output, using just their bare eyesight as a testing meter. Human eyes are prone to deception specially in the case of lumens calculation Lol. All the area which was initially lit by halogen glare is now lit by HiD glare.. not improved.
Secondly, its not just the shield that blocks the light in an HiD Projector but its internal reflective surface plays an integral part which is designed specifically for the focal length of a HiD bulb to concentrate and distribute (spread) the light as intended. the shield make sure the light stays within that distributed limits..
Reflector HiD lights (Thai Accords, JDM Premios etc) had their headlights designed specifically to take an HiD bulb (usually D2R) from the concept stage. Its highly unlikely to achieve that kind of cutoff from a Reflector Halogen setup.
