Brightest headtorch? Not quite

Not even as bright as my home-made one which has 3 of the latest high power LEDs (which are not only brighter than the 5W ones in that, but also only draw 3.5W each).

The current prize though I think goes to the new Lupine Wilma which has 4 of these new LEDs, and so should be more than twice as bright as that (the downside being the huge price)!

As to who needs such a thing, then you're right about the ARs and fell runners, but more particularly for going orienteering at night, for which the current standard is a Silva 20W halogen - though my home-made LED outshines that.

What are you using Chris? Cree X-RE?

I'm thinking of sticking a P4 in my Myo XP.

HOPE also make a HID based light, much better than their LED jobby in many ways, brighter and longer burn times. On the down side it does cost a wee bit more and you can't drop it like you can an LED. It looks like it will also fit the head mount adapter shown in the photo so I guess the LED lamp shown is not the brightest head lamp they will do.

If you buy or make any LED based lamp you will get lamp envy when somebody with an HID lamp walks or rides past!

The foot based outdoor kit manufacturers could learn a lot from the cycle industry, you just need to go to a night orienteering event and see how many people use bike lights strapped to helmet mounts to see that there was nothing on the market. Good to see the guys from Lancashire branching out like this. The Silva lamps are over priced and over here!

Will the head band be available for those that already own the bike lights?

My question exactly James, I do hope the head-cradle will be available separately, since the lamp unit looks identical. I already own the Hope as a bike light and it's great. I found it powerful enough to ride rough downhills at night, and it's beautifully engineered too. But now I use it mounted on my cycle helmet since I blew the budget on a Lupine Edison HID - now there is a light to cause lamp-envy, lol! Cars slow down as they approach you because they can't work out what you are, either that or they're just blinded!!

Since I got into night-biking this year I've been wondering about the transfer of the technology into mountaineering etc. I suppose one potential drawback is the power-usage and the use of bespoke lithium ion rechargeable cells - fine if you're out for a single session and then back to base to recharge, but not much use for an extended trip.....

Oh, come on, give us some more details about your headtorch.

What LEDs are you using (Luxeon, Nichia, Cree?)
Where did you get them (ultraleds?)
How have you arranged them into a headtorch?
What are you using as a heatsink?
How are you powering and controlling them?
How are you measuring the output?

Pretty pictures, please...

;-)

Some details and pictures at http://www.candlepowerforums.com/vb/showthread.php?t=147395&highlight=bike though the electronics has now gone surface mount and got a lot smaller than those pictures - I'm using Cree XR-E LEDs. Output measured using the mark 1 eyeball and comparing brihtness by shining it on distant trees.

As to getting lamp envy compared to HIDs, I don't think so! Not not only is my LED light more durable and allows me to dim the light efficiently for longer run times, but it also gives out 500 lumens on high, which is close enough to HID to not really notice the difference. Not convinced by your longer run time comment either, given that the HID uses more power, so that would only be the case with a bigger battery. Anyway, the Lupine Wilma I linked to above puts out more lumens than an HID.

I do a lot of night-O (I compete in what I believe is the biggest night-O league in the country), and very rarely see anybody with a bike based light - the big Silvas work very well compared to any equivalent bike light, and aren't particularly expensive for what they are either - much cheaper than this Hope light for similar light output.

That's quite an impressive contraption Chris!

But for those, like me, without the practical bent, (and especially if you already own the Hope Vision LED bike-light), I've just spoken to a very helpful chap at Hope and yes, the head-cradle/mounting is going to be sold separately and will fit directly the lamp unit and the soft-pack version of the bike battery. They're still sorting out the details and expect to be ready with them sometime next week. It'll be available directly from them - I just rang the number on the Vision-Adventure website link from Jon's report. They didn't have pricing ready yet and didn't want to say anything misleading, so please take this as an indication only, but it sounded like the requisite bits may be of the order of £25.....

Must be in the North West that we use bike lights with helmets for foot O'.

I am not saying that LEDs give off less Lumans than an HID but I do think that lumens is not a good indication of usable light, when compared to Lupines own HID Edison lamp and the Light and Motion ARC Ultra (both of which I have used extensivly including both at the same time!) the Wilma is left wanting. It may be that you don't notice this at slow speeds on foot but on a bike the 'usable pool of bright light' and not 'the distance that you can make a leaf glow on the hill side' is what is important.

If you want to rip along at high speeds HOPE HID beats HOPE LED no question, I have tried them both.

Granted not many of the HIDs are dimmable, the 2 I mention 1st are. I will be using the Lupine Edison HID at over night bike events this year, I am in the fortunate position of being able to choose to use the Wilma if I wanted to but I won't.

If I wanted burn times of more than 8 hours on one charge and did not need the amazing light output that you get from the Edison 10 then I would go for the LEDs and run them on low.

If you want the latest brightest LED I understand that Luxeon is making them, you can buy Luxeon bulbs from Farnells. Details of how to build a lamp with them are on the Luxeon web site. Slightly techy but east to follow. Careful with the heat sinks, LEDs run HOT! I bought some a while back with a range of lenses to play with but there was to much of a 'halo' on the light for me to use it. Better lenses may be around now.

Obviously different bulbs suit different applications. You pay your money and make your choice.

The point you're missing is that I'm talking about a different Wilma to you - the one I'm suggesting is the latest one upgraded with the newest LEDs, which is over twice as bright! I don't dispute that the Hope HID is brighter than the Hope LED, but then that uses older less efficient LEDs, as does everything else on the market you'd have seen (the only exceptions are the very latest upgraded Wilma, and the Dinotte 500L). Mine using the latest LEDs is significantly brighter than anything you can buy apart from the latter two, so you're comparing apples with oranges. I'm guessing that as you suggest Luxeon for LEDs you're not aware of this next generation which aren't made by Luxeon (rumours are they have something even better coming out soon, but at the moment they are well behind in performance), and the Luxeon bulbs Farnell sells definitely aren't the way to get a powerful light.

My point about run times is that the higher efficiency allows you to use a smaller battery. The battery I now use for night-O is only 100g (so complete system is <300g), which still gives me 1.5 hours on highest setting, and would give 4 hours on a setting equivalent to that Hope light. Your HIDs might be dimmable, but the lowest you can go is still ~10W, whilst you can go down to 1W with my LEDs (which is still rideable with when climbing - I've tried it).

Where are you getting your Cree LEDs from, Chris?

From Cutter in Australia though LED-TECH also do them now.

Ta. I can see myself down the PCB room with some alumina substrate before long...

What method are you using for brightness control? PWM or Vf? Given the versatility of modern SMPS chips, I think it would be pretty easy to rig up a Vf drive by controlling the Vref input of a suitable SMPS device. I'm sure I have some suitable candidates lying around... If not, Maxim will send me some...

Just thinking about the heatsinking requirements. For a headtorch, I guess the only criterion is to ensure a good, simple convection airflow. For bike use, assuming you're actually moving, using the forward motion to give some forced air cooling might be useful, so fins at the side.

And how about linking the drive current to your speed? <chuckles> The faster you go, the further ahead you need to see, so the brighter the lamp...

A NEW NEW Wilma, didn't see that one coming! Will be curious to try it when it is available.

It has been 2 years since I was playing around with Luxeon 5 bulbs (Farnells were the suggested UK source for non trade buying at the time.) Luxeon still claim to make the brightest bulbs and have one that they are about to launch that can achieve 502 lumens at 8.3 watts or 135 at 1.2 watts. http://www.lumileds.com/newsandevents/releases/PR64.pdf

The Cree bulbs look like they are much more suited to DIY projects with more support, correct me if I am wrong!

What is the spread of light like on the new LED lenses? One thing I realy like about the Light and Motion HID is the huge flood of light and the distance it throws. There are no dark spots at all. With ref' to bike lights it is hard to argue that it has been the best lense on the market for some time now. When I was messing about with LEDs and trying out loads of commercial systems I could not get close to it. If this new range of LEDs can challenge that then my HIDs may be on Ebay soon!

I'm using a commercial current regulator - a Taskled Fatman. This is a boost driver, so operates with a lower voltage battery than the LED voltage. Regulation and dimming is by current control - no PWM, as that's less efficient - you should also be aware that with LEDs you regulate the current not the voltage. My home built electronics is simply an AVR providing single button level control of the regulator.

I presume from how you're talking you know enough to build your own regulator - in which case, the chip on the one I have is an LM2700. This is nice and efficient - I get 90%+ - which is something you need to watch with some converter chips which only manage 70-80%. To make it current regulated simply have a current sense resistor with the output fed through an amplifier to the Vref input (I'm actually using the amp as a comparator and feeding it a voltage from the AVR to control the level - though I have plans for a redesign where I control the amplification instead for better stability).

Luxeon's claims are rather outdated - they seem to have quietly ignored the new releases which have been around since October, and not updated their site to reflect the new reality that they are no longer the performance leader! Note that October was when these became available to people to buy - at the moment that new Luxeon is still just a press release, and they also apparently use slightly dodgy measurement techniques to get their headline figures (very short 10ms or so pulses). They will probably be the best when they come out, but then only 10% or so better than the rest - the XR-E which came out in October was almost twice as efficient as anything else on the market at the time!

Don't understand "more suited to DIY projects" - do you mean easier to use for that than Luxeons, or worse for commercial users? I don't think in reality there is much difference with either - the reason most commercial lights still use Luxeons is simply timescales and commercial inertia, as the XR-E has only been out for 5 months.

All sorts of different lenses available for these new LEDs, so I'm sure there must be something which would suit. I actually really like the Cree optic I'm using (though am planning on trialling some others soon), as they give a very strong centre spot, but still a reasonable flood spill around the edge.

By 'more suited to DIY' I mean just that, not reffering to the commercial side there.

There appears to be a greater range of simple mix n' match bits for those of us that know how to solder but not chase that extra 10% battery life like you can.

I'd have thought the Luxeons are actually slightly better suited from that POV, given there's plenty for them out there. Very easy now to get hold of the Cree XR-E (and the similar performing Seoul P4) and lenses for those though, so it's not really an issue either way.

I'm not really using anything on the LED side which you can't get and use quite easily to make something which performs just as well as mine (if you've got machining facilities you can probably do better - my biggest problem is with housings). It's only on the battery and control bits where I'm doing stuff which isn't quite as simple.

> you should also be aware that with LEDs you regulate the current not the voltage

Yes, I am aware that this is the usual method adopted by LED driver chips, but I was looking at the If/Vf and If/Po curves and thinking that it might be possible to do a simple Vf drive. Of course, there may be too much production (and temperature) variation in the If/Vf curve to make this viable (i.e. the risk of current over-driving an LED with a low production Vf).

Just out of interest, there comes a point where you can arguably, in some situations, have too much light. One of my mates, who is a bike journo, rode a night lap at one of the 24-hour races using two sets of top-end Lupines. He actually had to use the lower setting to avoid blinding himself from bounce back off trees and other riders.

LED technology is developing all the time to the point where it's catching up with HIDs. Oh, and fwiw, most HID bike units are still too heavy to headmount in my experience.

My nightlap set up for 24-hour races is a Lumicycle HID on the bars with a 35-watt halogen spot on my head. I find it hard to think of a situation where I'd need any more light than that :-)

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OutdoorsMagic Editor | jon@outdoorsmagic.com 

I'm inclined to agree Jon. I reckon my Lupine Edison HID would helmet-mount ok but I wouldn't want the battery (not even the '5' unit, let alone the '10' bottle battery) up there. The Hope LED and it's softpack battery though do mount very nicely on my cycle helmet so I reckon they'll make an excellent headtorch unit as soon as I can get my hands on the cradle.

As for too much light, well yes to that too. I began night riding this winter with the Hope LED on the bars and an old Black Diamond halogen headtorch on my helmet - it worked ok but the halogen light seems off-puttingly orange in comparison! Once I got hooked enough to buy the Edison (16W or 10W HID settings) and move the Hope to my head the combination is superb and I wouldn't want any more - it may be different for racing but for general riding, well you want night-riding to be different so there's no point turning it into daylight out there!

One problem with super-bright head-mounted lamps though is definitely the 'dazzle you mates' factor! It was always bad enough even with the old faithful Petzl Zoom, but stick something as powerful as a car headlight on your forehead and.....!! ;O)