It's pointless having LED DRL's on at night because they're what's called a passive light and hardly illuminate the road.
Robin I disagree with you there.
Forgive me, but I think you may have misunderstood the Red leader. I think Red was trying to state that DRLs are NOT intended to illuminate the road ahead, DRLs are simply to attract attention from other road users - similar say to strobe lighting on aircraft.
I knew that was just pointing out that an LED Light Source can be used to illuminate rather than attract attention
Ho kay.
My DRL's give quite a lot of light actually and light up the area immediately to the front of the car quite well.
That may be the case - but they wont (or shouldn't) throw a 'beam' of light down the road similar to either a conventional dipped beam, a conventional fog lamp, or a conventional main beam. Basically, you couldn't drive down a pitch black road at night with only your DRLs - and successfully navigate in the same proficient mannner as you would with headlamps.
Correct i couldn't but there again if i use my NVG's
Got a secret stash to share?
Also LED can't be that bad considering the R8 V10 has LED headlights.
Yes, agreed. But those all-LED headlamps were painstakingly designed (it actually took them longer than they planned - rumour has it they were initially wanting them to go on the R8 V8 when it was first launched). And from the early mixed feedback, they arnt as good as the Xenons!
Having seen them against the R8 V8 HID's there is no discernable difference to the Naked eye of light output.
It wasn't the actual intensity of the light output - ie, the measure of lumens, which was the problem. It was actually trying to correctly focus the light output from the LEDs into a satisfactory 'beam' which can be appropriately measured (you must have seen the distinct shaped of a dipped headlamp beam on your garage door or similar), AND the ability to adjust said beam level to cope with differing vehicle loads (the dash-mounted thumbwheel to manually level halogens, or the automatic self leveling of HIDs - for when you have a couple of fat burds in the back).
From what I have been reading lately manufacturers are starting to do more research into LED technology as they can get more light for less power than halogen or HID.
LEDs can certainly be better than tungsten and even halogen - which is why they are becoming common in tail lights. The jury is still out on the LED vs HID arguement - yes, LEDs will consume less power than the 35 watt HID capsule - but in the R8 application, don't they need sommat like 130 separate LEDs to match the lumen output of a single HID? And the beam pattern of LEDs is considerably more difficult to engineer into a usable forward 'beam' (this was what took Audi so long to achieve).
Nope they Use 4 LED's for the Main Beam
14 LED for the Low Beam (No i haven't got them the wrong way round)
8 Yellow for Indicators
24 LED for DRL
See Here:
R8 LED Headlights
I'm not too sure how acurate that WCF article is. My stealer told me there were sommat like 130 per headlamp housing, and I have had a close look at an R8 V10 - and yes, there are only 4 monster LEDs for the main beam, there
looked to be considerably more for the dipped beam - unless it was the internal reflector playing trickery!
Also you say it's more difficult to direct the beam I am confused because all the work that we do in my job with various companies who provide us with light sources (majority of which are LED these days) it's very easy to get the beam exactly how you want it. But im not a lighting engineer so maybe it's different for car headlights.
OK, if you look very carefully at a naked LED (not one which has its usual clear plastic dome attached), an LED emits light from basically a flat surface, ie, in a single plane. Other light sources, be they tungsten filament or a HID capsule, they emit light in all directions and in all planes - in three dimensions if you will. Therefore, filament and HID generated light is considerably easy to 'reflect' or 'difuse' into an appropriate beam pattern, whereas surface emitting LEDs are considerably more difficult. Being as modern headlamps now only use plastic outer lenses/covers, the 'difusion' method of generating a beam (see old headlamps with glass outer lenses - with all their internal ridges in the glass), the only available method of generating a beam is reflection. Now, look side on at a tungsten or HID headlamp - the light source is always infront of a reflector, and the light is 'collected' from a rearwards 180degree angle (and either focussed through a fish-eye projector lens [HID], or just passed through the outer plastic lens [filament]). You can't do this with LEDs - you basically need to 're-invent the wheel' to get LED light output into a focus-able and definable beam pattern.
Oh, and another snippet of useful info - because the pattern of the light beam is now only generated by reflection and not diffusion, this explains the prevalence of headlamp washers on cars with plastic outer headlamp covers - and why it is also vital for HIDs to have washers. Because any cr@p on the outer plastic will difuse the beam beyond its normal design parameters.