Any ideas if these are any good? I'm looking at buying some of these as we all know the TOC-H lamps ain't good at night. Especially being blinded now in comparison to all the LED/HID retina burners mixed with LHD lorries without lens converters out there now
Seriously weird beasts. Normally projector lamps go under a simple transparent cover so the lens does all the beam shaping work. I have a pair of the 3" diameter H1 halogen breed on my motorcycle and they work just fine behind the plain glass cover.
P38 headlamps have beam shaping block lenses on the front intended to work with light coming off the reflectors to give the right beam shape. With a normal bulb pretty much all the light comes out sideways and up-down ways to bounce off the reflector. Opaque cover on the end of the bulb stops pretty much all the direct light.
Those bulbs have a very small lens and project a long way into the light unit. Presumably the theory is that the projector lens is pretty close to the headlamp lens and pushes light through only a small section in the middle so the block lens doesn't do much. $64,000 question is how much effective lens the beam sees. If were longer so the projector lens was close up to the headlamp lens I'd be much more confident that it would behave.
Other issue is whether you can actually get them into the P38 headlamps without removing things to make way. They are effectively about 5 times as long as a normal H4 and the business end pretty much fills the hole so probably need to be slid in straight on. I always tilt the halogen bulb to get it in or out.
I see that Powerful UK have their simple halogen replacement LEDs back in stock. £45 the pair - https://www.powerfuluk.com/vehicles/range-rover-full-size/p38/exterior-accessories/h4-led-4000-lm-headlight-bulbs-white-pair.html - at least we know they work OK with acceptable beam pattern.
Clive
The Powerful UK ones are those that Orangebean fitted into his and after a bit of faffing around got a near perfect beam pattern. I tried some from eBay, not the ones you are looking at admittedly, but there was no way the beam pattern could be considered acceptable. The Powerful UK ones have dropped in price too, they were about £75 before, so I stuck with my preferred Osram Nightbreakers.
Ordered pair of those LED bulbs from Powerful as they are now below my £50 "looks OK, give them a try" threshold. Will report back.
Further to those projector style devices I have worked with that style of optical system where a source with projection lens is moved towards and away from a larger block, fresnel or other "patterned" lens to change the output beam shape. Works well if properly designed but I'm told the designing the lenses is tricky. Can't see a one size fits all device being optimum although it may work well enough on some headlights. Bulb flange to headlight lens distance will be the critical parameter.
If you look at the P38 headlight there is a lot going on close to the middle of the block lens. Wet finger in the wind guess is that a projector beam diameter anything significantly more than 2 inches or so diameter where it passes through the lens will have serious stray light issues. Doesn't help that the P38 has a rectangular reflector with the lens tilted sideways.
More chance with the modern type of headlamp having a stepped reflector and clear cover. Especially if the cover is simple and not variable thickness to act as a lens. Probably have to take half the front of the car off to fit one tho'.
Avoid I think.
Clive
Although it’s against my religion to spend this sort of money on a set of bulbs, now with winter coming , price reduction, failing eye sight , and just fed up with people not seeing a f-ing great Range Rover coming along the road. It’s time to either get these or buy every other A-hole around here a set.
no10chris wrote:
Although it’s against my religion to spend this sort of money on a set of bulbs, now with winter coming , price reduction, failing eye sight , and just fed up with people not seeing a f-ing great Range Rover coming along the road. It’s time to either get these or buy every other A-hole around here a set.
I hear you!
My only concern is they are 6.5k, that's Eastern European old BMW M3 boy racer addon colour. I prefer white 4.5 - 5.5k as apparently the more blue the light the more it disperses in the atmosphere due to water and the less distance it travels. Please correct me if I'm wrong though as I can't remember where I read that.
I ran 6K HID on my bike and with my old yellow night visor it was not a good mix! I couldn't see much as it all went green ( hindsight is a wonderful thing). I took that HID off and went back to normal bulbs. MV's are good lookers but as super models they like daylight and posing not parading in the dark, the dip beam is seriously crap. I had to wire my dip and main together to even begin to see things. Honda's have some of the best lights I've ever ridden with.
I've got night breakers now though hehehe. The normal main beams are probably the best I've ever had on a car but it's the dip that is the problem, it's crap and it gets over powered by all the new cars LED retina burners.
Mukiwa wrote:
the dip beam is seriously crap.
You want to try a Yamaha Fazer then for really crap dip beam. They've got twin headlights but as standard one is dip and main the other main only, I've rewired mine so they are both dip and main and even then dip is only marginally better than a candle in a jam jar. I did consider trying one of the LED bulbs that I bought for the car and condemned for the appalling beam pattern. I suspect the fork leg would remove the heatsink on the back of the bulb when I put it on full lock though.
It's worth checking the reflectors on your headlights. They do deteriorate over time and reduce light output.
Mukiwa wrote:
My only concern is they are 6.5k, that's Eastern European old BMW M3 boy racer addon colour. I prefer white 4.5 - 5.5k as apparently the more blue the light the more it disperses in the atmosphere due to water and the less distance it travels. Please correct me if I'm wrong though as I can't remember where I read that.
I ran 6K HID on my bike and with my old yellow night visor it was not a good mix! I couldn't see much as it all went green ( hindsight is a wonderful thing). I took that HID off and went back to normal bulbs. MV's are good lookers but as super models they like daylight and posing not parading in the dark, the dip beam is seriously crap. I had to wire my dip and main together to even begin to see things. Honda's have some of the best lights I've ever ridden with.
I've got night breakers now though hehehe. The normal main beams are probably the best I've ever had on a car but it's the dip that is the problem, it's crap and it gets over powered by all the new cars LED retina burners.
Aren’t the ones above only 4000lm, which should be nice and white
You're confusing the units Chris, LM is Lumens, the measure of brightness based on the Candela where 1 Candela is the brightness of 1 candle (OK so it gets more complicated depending on whether you are measuring it as a spot of light or the light that is emitted in all directions) so basically 4000 LM is 4000 candle power, but K is Kelvin, the colour temperature. That is based on the colour of light from a piece of heated metal so at lower temperatures the metal gets red hot and as the temperature gets heated more, the colour gets brighter and whiter until it starts to get a blue tinge to it. You will sometimes see light bulbs, and especially fluorescent tubes, described as warm white (lower k figure) or bright white (higher k). Have a read of this https://www.ledexpress.co.uk/blog/whats-color-temperature/ which explains it and gives the K figures for different light sources.
What Mukiwa is saying that at 6.5K the light from these is going to be very blue, maybe too boy racer blue. However, assuming these are the same as the ones Orangebean got from PowerfulUK and fitted to his car, they didn't look overly blue. When he and Morat were following me to the hotel at last years summer camp, his lights were noticeably brighter and whiter than the standard Halogens in Morat's car but didn't look too blue.
I understand the colours ect, they go from sort of yellow to purple, I agree that 6500 will be blueish, I need to find the chart I looked at before when I was looking at bulbs
6.5K should be a fairly pure white - with maybe a hint on the bluer side.
Most of the boy racer 'cool' HIDs are up around the 8000/10000K mark which has the really distinct blue tinge to the whole light output
In practice higher "colour temperature" LED bulbs will seem brighter for any given input power due to the way they are made. Usual construction appears to be a high efficiency blue LED emitter with phosphors to down convert some of the blue emission to other colours. Nominal red and yellow phosphors seem to be common in headlamp bulbs.
Higher colour temperature specification bulbs let more direct blue radiation through and divert less to the phosphors. There are significant energy losses in wavelength down conversion via phosphors so letting more blue through clearly means more light for the same input power. The blue wavelength is also quite close to the peak sensitivity of the rod cells in the eye. Rod cells are pure intensity detectors and play no part in colour vision. They are very sensitive indeed, almost single photon sensitive in ideal conditions, and do pretty much all the work when the eye is dark adapted. So not only do you get more light power out of higher colour temperature bulbs that power is where the dark adapted eye is most sensitive so things look even brighter at night than pure power calculations would suggest.
Applying colour temperature specifications to LED bulbs is scientifically fraudulent. Colour temperature applies only to incandescent light sources whose output over the appropriate spectral range is adequately close to that of true black body. For quantum physical reasons (Planck's Law) the spectral output power curve of a Black Body is the same shape whatever the temperature. The peak just gets higher and shifted to a shorter wavelength as it gets hotter. http://earthguide.ucsd.edu/eoc/teachers/t_universe/p_blackbody.html Basically just grab the peak of the graph and drag leftwards and upwards.
Can't find good picture of white LED spectra on t'net but plot b "W-LED" here https://www.researchgate.net/figure/237151257_Output-spectra-of-the-colored-light-sources-a-fluorescent-lamp-b-W-LED-c shows the general idea. A sharp blue peak with a hump lower down, mostly yellow & red. Colour temperature is assigned by finding a temperature at which the blue peak and yellow-red tail of the LED output pretty much touch the black body curve.
Really the whole thing only sort of works because of the human brains remarkable ability to interpret the eye output signal so colours and shadow intensities are seen pretty much consistently over a huge range of light levels and source colours. When it comes to apparent colour what you see is along way from what the eye got.
Clive
Which is why a camera will show the differences in the colour of light but you don't notice it yourself. Even daylight changes in colour between early morning and evening. A camera will show that but to you and I it is just light. But this does lead on to a question I have pondered many times, do we all see the same colours? I can look at something and say that it is red, another person will look at the same thing and agree that it is red. But is the colour that I see and call red the same colour that you see and call red?
What Mukiwa is saying that at 6.5K the light from these is going to be very blue, maybe too boy racer blue. However, assuming these are the same as the ones Orangebean got from PowerfulUK and fitted to his car, they didn't look overly blue. When he and Morat were following me to the hotel at last years summer camp, his lights were noticeably brighter and whiter than the standard Halogens in Morat's car but didn't look too blue.
Correct Glibert, that is what I mean, but I would like to hear a real world report from someone in the unlit countryside as to how good they are in the dark AND against oncoming lights. That's my big problem, Rommel's TOC H lamp light seems to vanish against all the modern eye burning LED and LHD car beam. I love a bright light as good as the next night driver but I wish the lights actually pointed DOWN at the road and not into my eyes. One of the worst I can be in front of or have coming at me is the Nissan Juke style froggy on top headlights with a beam that seems to be almost 360 degree and everywhere but the road.
Orangebean fitted a pair of the PowerfulUK ones to his car and followed me at last years summer camp. Bright white, not too blue and definitely bright but didn't cause me to have to dip my mirror. Admittedly he had spent a while setting them up properly but they did seem to be very good. Totally agree on some modern cars with the headlights mounted high up (although the Nissan Joke should have been aborted before birth anyway) but there's others that seem to be pretty bad too.