DIY Retrofit Legit Projector Headlights Projector + HID Mod < link My first two prototypes were experiments with the H4 sealed beam replacement housings with HIDs. DON'T USE THEM. If you don't have a contrast between light and dark like below, you're doing it wrong! However, some of us have opted for HID's in our H4 housings just because we can. This provides issues because THERE IS NO GOOD H4 HID "conversion" kit. THEY ALL SUCK. There are 4 kinds of H4 hid's with low/high beam and a combinations of both or either. The goal of this thread is NOT to argue whether or not HIDs are bad in reflector housings, it's to produce the best beam possible with HIDs without fabbing up proper projector lens into our cars. If you're gonna use HIDs at all in any H4 housing, I suggest sticking with H4-1. This is only low beam and this way, we can focus on one light source aiming the right way. Let's start with a standard H4 run of the mill bulb. You'll see that the top shielded portion is the low beam and the high beam is the bottom portion. The shield makes sure the light beam only goes to the top of the reflector. Top of reflector = beam towards the ground. The unshielded bottom portion allows the light beam to reflect on all parts of the reflector = beam pointed straight forward. Now if you compare your regular "H4 HID conversion kit" bulb with the bases at the same height. You'll see that where the HID light arc is nowhere near the low beam OR high beam, this is the reason why H4 HIDs give a different cut off than standard H4 bulbs in the same housing. So I'll be sharing my findings here over the next few weeks. I've been experimenting with spare H4-1 HID bulbs. The goal right now is to match the location of Filament in Halogen vs. Arc in HID. Prototype 1 (fail): Pic 1: Disintegrate the base where the bulb sits and move the whole bulb up. Pic 2: Line up the HID arc to where the low beam H4 filament is. Note the base should be the same height. Pic 3: Left: Modded HID, Right: Untouched HID (I put back the Casper Shield back before trying out pic 4) Pic 4: Left: Modded HID now has cut off, Right: Untouched HID with glare. Both in Autopal housings. Different color because the test bulb on the left is 6000k while my daily usage bulb right now on the right is 4300k. Two notes: 1) This won't work because the plastic base is made out of some material that insulates high voltage and prevents voltage arcs from forming between the two wires. When I broke it off and sealed it back with electrical tape, 20000 volts just goes through it. Seems to have only affected off/on cycles. Hot bulbs need more voltage to start up the light arc again. 2) If you look at a standard halogen H4 bulb facing down, the bulb compared to the base is rotated a few degrees clockwise, this provides the rise up light towards the right side (see first picture of thread). I will need to rotate the Casper Shield clockwise to reproduce this effect.