Petzl's Nao Goes Running

We introduce Petzl's clever new head torch to a serial night-time fell-running addict.

Posted: 28 March 2012
by Richard Seipp

Anatomy of the Nao - top 'bulb' is actually a light sensor, bottom left spot beam, bottom right, flood. When light levels are high, the Nao uses just the flood, but as it gets darker, the spot comes into play. The transition is near seamless and hard to detect.
The chunky, square switch on the side of the light body is, for once, massively easy to use, even wearing gloves or heavy mitts.
Novel part cord / part elasticated strap harness is both comfortable and stable, even for off-road running use. Impressive stuff.
Optional top strap is non-stretch, too narrow and not really needed anyway.
USB rechargeable - lead supplied makes access to masked ports straightforward.
Production Nao may gain forehead cushioning, but were not sure it's really needed anyway.

OM regulars will know that we've got an advanced sample of Petzl's new for 2012 Nao head torch to play with - it's a highly ingenious, very bright light with one massive stand-out feature: it can be set to automatically adjust the light output using a  sensor, so the claim is you get as much light as you need, but with optimised battery life too.

It just happens that our friend Rich Seipp is a long-time Peak District fell-runner with a passion for running in the dark and currently in training for a second crack at the epic Bob Graham Round of the Lake District's 3,000ers. On paper it seemed like a match made in heaven, so we threw the Nao - carefully - at Rich to see what he made of it. Over to him...

Testing The Nao - Rich Seipp

I run at least once a week in the dark on the fells, and a powerful head torch is a must. The Nao with its reactive lighting on paper at least looks to be just the thing and I had the opportunity to use it for two night runs.

Plug And Go?

To charge the battery you unclip it from the rear of the head harness and plug it into a USB socket on your computer. There is a battery fuel gauge which tells you when it is charged. Straightforward enough.

The nylon cord head harness gave a good fit on my head. Initially I also fitted the optional band that goes over the top of ones head, but I soon removed it as due to its narrowness, I found it cutting into my balding bonce like a cheese wire. The whole thing weighs 187 grammes and, without the top-strap, is comfortable to wear. 

The large square on/off knob was easy to operate even with my pile mitts on. There are four modes to choose from, high and low “Reactive” that is variable power depending on what the torch is pointed at, and a high and low constant setting. I mainly used the high “Reactive” setting, though on fast downhills I opted for the high constant setting. When not in use there is a locked off setting so that the torch isn't accidentally turned on whilst in your bumbag or rucksack etc.

Car Trouble

The first part of both my runs heads out along lit roads. The torch in “Reactive” mode initiates a fairly low beam. That is until a car with headlights approaches. Then it dips the beam, then as the car passes it turns itself up to max power before settling back down again. A bit annoying if there is lots of traffic, think disco lighting.

Once off road though, the light comes into its own. The beam has a good spread, yet with a centre weight, without sharp edges. Running up hill on rough paths and on the flat, the torch was just bright enough. I could have done with maybe a little more light for illuminating the path just ahead. Looking way ahead into the darkness, the light brightened enabling spotting runners in the distance.

One amusing quirk was on a cold night, my exhaled breath would reflect of the light's sensor confusing it into thinking it was brighter than it really was resulting in it dropping the power. I presume on a misty night it would do likewise.

Going Downhill

On fast steep descents I put the torch on to full power - 315 lumens being more than plenty to illuminate running downhill as fast as I'd run the same stretch in daylight.

Over the two runs without a re-charge between, the battery lasted just under 4 hours used mainly in high reactive mode with  20 minutes of that on full static light mode.


A comfortable, secure head torch - the unusual head harness works well apart from the optional top strap, which isn't really needed anyway. It gives a good wide beam. but as tested I didn't feel that the torch was quite bright enough in high reactive mode, though this may be remedied when the Petzl OS programming software is released for this model. [We're still not sure what options on the torch will be programmable. Ed]

The downside of the reactive lighting mode is that mist and car headlights can confuse the light's sensor, and in these circumstances it would probably be better to use one of the fixed light level modes for.

What's Next?

The Nao's not actually out until July, so we've got plenty of time to give it a bit of a hammering. Adding to Rich's observations, we'd say that so far, we've found the ergonomics of the torch excellent. It's comfortable, very stable and the chunky twist switch is really easy to use even with gloves.

It will be programmable with Petzl's OS software, though we don't yet know which aspects of the light's performance will be variables. Charging is straightforward and there's an extension USB socket cable supplied. Battery life on the 'Reactive' setting is variable and depends on use. Rich's burn time of around four hours seems reasonable and, for a comparison, we're going to check it out on full static juice soon.

And finally, though he's not said so himself, as an experienced fell-runner on his local trails, our man Rich moves pretty fast when descending, so even though the reactive setting isn't quite bright enough for him on the downs, it may prove to be sufficient for more cautious runners. We'll check that out personally...

So all in all, pretty promising we'd say.

Petzl Nao - Brief Spec

• weight - 187g
• max output reactive - 355 lumens
• max output static - 315 lumens
• burn time - 4h40 approx (reactive) 1h20 (static)
• Li-Ion battery charged via USB socket (lead supplied)
• 3-yr guarantee for lamp, 1yr for battery
• optional Nao belt kit with extension cable
• available in the UK in July 2012, SRP: £135 

More info at

Previous article
Advertorial: 10% Off Columbia Products
Next article
Win A Columbia Omni-Dry Jacket Worth £195!

Petzl Nao

Discuss this story

I was wondering about the point regarding the mist and the light turning itself down. I would have thought this was a good thing as fog reflects the light back in your face blinding you so you wouldn't want it on full power.

Posted: 28/03/2012 at 21:10

I was pondering this and I think that's probably true - what I suspect might be annoying would be a scenario in variable conditions where the light's intensity could vary according to the thickness of the fog particularly if you were running and light conditions changed rapidly.

The answer, I suppose, would either to use the static light low setting and/or take it off and use it as a hand-held torch maybe. Certainly with bike, powerful helmet lights are near useless in fog because of the amount of reflected light, bar lights work better because they're further from your eyes.

Not much fog around at the moment mind.

I wonder how it'd cope with a particularly thick plague of midges...

Posted: 28/03/2012 at 21:33

Been using a Nao for a few weeks now in fog, on clear nights, running toward cars at night with lights on and all sorts, and totally love the adaptability o the light. It reacts so fast it's hard to believe... On really cold nights I'd dims slightly with breath mist rising past the light so it doesn't blind you with the reflection. And you can see as far in the fog at night as you could in the day. Guess well just have to wait for infrared headlamps that plug directly into your retina to see further through fog at night ;c).
Awesome torch...

Posted: 30/03/2012 at 00:00

See more comments...
Talkback: Petzl's Nao Goes Running

Sign up to our weekly newsletter
Sign up to our twitter feed