Does this increased brightness come from a larger current through the LEDs or from higher efficiency LEDs? If it is the former then battery life will be reduced.

Parahandy/ptc/Chief Engineer - "I said this was happening a few weeks back and I got shot down in flames."
Hi, are you referring to this thread?

Doug M - The XP headtorches are unchanged. Don't worry, you've got the brightest Tikka there is!

Richard Want - I was chatting to one of the guys at Petzl and he told me they were planning a TacTikka XP.

Geoff - Tactikka XP is in the offing but later this year or possibly early 07.

I'm starting to hate petzl, they keep making me want to spend my hard earned money on better and better products.

The problem is that torches aren't just shiney but they actually give out light which is even better. If someone tells me that a new fabric is more breathable then I can't see the effect so it doesn't work on me. If you tell me a new torch is brighter I can point it at a shiney object and go wow and then hand over my credit card.

I wish you'd just go away for a year and come back with the perfect torch, preferably one I can point at the space station and see it bounce back and weighs 5 grams and only needs new batteries once every hundred years so I can buy it and not have to keep buying ones that are only 80% brighter than the last ones.

Geoff, aye. But I couldn't find it again when I went through the bumff, only the bit we mentioned.
I lost sleep over that you know :o)

Chief Engineer - Hehe.

John Bailey - So you don't want to know that Luxeon leds are old news and it's all about the new K2 emitters then? :-)

Check out theCandlepower Forums for all the latest in illumination.

<puts credit card out of sight>

What these LUXEON K2 Emitters]

I have to say that the light source is not the only thing that is important. What makes a huge difference is the reflector and lens combination (referred to as the Optic) which channels and concentrates the light output where you want it whether narrow beam or wide angle.

LEDs have always had an element of directionality built in via the integral lens but modern reflectors can guide stray light into a narrow penetrating beam wich provides excellent range over a very small solid angle.

The Petzl reference system details how they measure effective distance and beam angle and is an excellent guide..... however everyones eyes are different and requirements are different.dont forget that your eye responds differently to different wavelengths of light.

A green emitter optimised for 556nm would appear to produce more light than a white emitter but everything would appear as shades of green and would probably not appeal to most headtorch users

I find that the option of having a general diffuse light for close tasks and a higher intensity light which can be focussed for distance work provides for every situation that I've encountered.

I look forward to comments and will be experimenting with green headtorches in the near future

John Bailey - you are right. It's an almighty pain that Petzl are continually great. As their press spokesman, it would be so much easier every year to send press releases that go "STOP PRESS - Petzl Are Great, Again". However, they keep innovating and I keep having to explain.

Doubtless you'll be haemorraging cash yet again in early summer when the new Petzl Meteor III helmet hits the shelves, after I've expained how great it is to O.M. Ho hum.

Thanks Richard.

Now, any chance of reducing the price on the Duo 14 LED?

> Does this increased brightness come from a larger current through the LEDs or from higher efficiency LEDs?

Given that LED efficiencies are increasing all the tiem, I think it's fair to assume that they've simply changed the LED they use to a more modern one. Not exactly rocket science, and the cheapo £5 torch I bought via eBay is far brighter than the Tikka I bought 5 years ago (and yes, I have measured the outputs with an optical power meter...) If I'd been in the headtorch market, I'd have expected to do regular LED upgrades as they became available. I'd also expect the LED prices to drop...

Power control is a double-edged sword, but, on the whole, I'd prefer to see a switched-mode LED regulation to allow the output to be controlled.

This _can_ increase the battery lifetime because the LEDs won't take so much current when the batteries are fresh. However, as the batteries run down, more current will be drawn from them than if using a simple resistive drive. And yes, such a control can result in an abrupt end-point unless measures are taken to reduce output in say, the last 10% of battery life.

So there's a trade-off between controlled brightness and lifetime.