Inexpensive H4 / 9003 / HB2 LED headlights ($32) - trying on the Prius & motorcycle

[PaulB2]

Too bad I recently finished installing relays to get my incandescent bulb voltage up. Wasted effort if I want to go with these LEDs.

One way to extend the longevity would be to switch in a resistor during the day when the ambient temp is high, thus limiting current when you don't really need to illuminate the road. Switch it out at night time when temps are cooler.

I hate blue headlights with a passion. I spent some time in France where all car headlights are yellow. That is much better for cutting through fog, yet it is easier on the eyes of oncoming drivers. I bought some yellow bulbs for my car here in Oregon and got pulled over by a cop for having non-standard bulb colors. Oh well, I guess my consideration for my fellow drivers was not wanted!

[topcat]

To get a replacement technology for a filament, the light emitting area&volume of the new technology needs to match that of the old filament.
This is reasonably feasible with an arc (HID).
In my view, multiple LEDs spaced apart are never going to match a filament correctly - especially single-sided LEDs which can only emit from one face.

For this reason, LED headlights need to be fitted to a projector designed from scratch for LEDs (IMHO).

[mcrews]

Originally Posted by topcat

To get a replacement technology for a filament, the light emitting area&volume of the new technology needs to match that of the old filament.
This is reasonably feasible with an arc (HID).
In my view, multiple LEDs spaced apart are never going to match a filament correctly - especially single-sided LEDs which can only emit from one face.

For this reason, LED headlights need to be fitted to a projector designed from scratch for LEDs (IMHO).

exactly!!!!!

[deejaaa]

Originally Posted by topcat

To get a replacement technology for a filament, the light emitting area&volume of the new technology needs to match that of the old filament.

if used in the old housing.

Originally Posted by topcat

This is reasonably feasible with an arc (HID).
In my view, multiple LEDs spaced apart are never going to match a filament correctly - especially single-sided LEDs which can only emit from one face.

For this reason, LED headlights need to be fitted to a projector designed from scratch for LEDs (IMHO).

i agree with you. same reason some people still believe you can retrofit HID's without using projectors.

[Daox]

I got the other bulb installed in the car today. I just got in from snapping a few pictures of it. The images didn't turn out as well as the first one I took, but here is the first one and the second one. The second one really looks identical to the first, but its a mirror image light pattern wise.

Halogen in left, LED in right.




LED in both.




So, the cutoff isn't super crisp, but it certainly isn't bad.

[freebeard]

Agreed.

Mine would have been putting circles on the garage door, on low beam.

In the one-each picture you can see a hot spot that the halogen doesn't have.

[serialk11r]

Originally Posted by Daox

So, the cutoff isn't super crisp, but it certainly isn't bad.

Hmmm, your halogen's pattern is kind of "complicated" too, I would say the LED isn't doing bad in that case. My LED headlamps arrive next week, can't wait to put them in. I can barely see at night with my stock halogens.

[Daox]

I drove the Prius at night for the first time with both of the LED bulbs in. The low beams are great. The high beams are horrible. I'll have to get a picture to show it. It looks like you just turned your lights on 50% brightness when you switch on the high beams. I didn't try to see the beam pattern against the garage to see what is actually going on. I just noticed it while driving home last night.

[mcrews]

http://ecomodder.com/forum/showthrea...est-27855.html
here is a thread on why the led (or any other light source fails)
as stated several posts up, the chrome housing is SPECIFICLY designed for a certain type of filament bulb.

What you are seeing on high beam is all of the light rays bouncing incorrectly off the chrome housing....going is all directions thus creating excessive hotspots and glare.



look at the 'FAIL" column. Some of the light is 15-20 TIMES GREATER than the allowable light to pass the test.
granted, it's not and HID it's an LED, but the principle is the same.
One light source CAN NOT (by the laws of physics) reproduce the same light spectrum as another.

[RedDevil]

We may as well put the graphical comparison for the same test from that thread here.

Left the original halogen, right the replacement HID, without realignment.


Check the alignment when you've replaced a light...!
If you don't, and it is out, and you don't correct for it, you may blind other traffic (and fail govt tests).

Of course, when the light source is misplaced in the lamp, or wider than the lamp housing design accounts for, that may cause trouble.

In the case of HIDs their 3x brightness would cause the stray light to be 3 times as bright too, even if the discharge area would align perfectly with the hottest part of the halogen filament.
Measures to reduce that stray light (caps, specially designed reflectors or projectors) might be necessary.