Spark SX5 vs Petzl NAO Review

The reason I became interested in Spark was a direct result of a visit I made to MEC around Christmas 2012. I was waiting for my PT Apex to be shipped back to me from the USA for the third time, and I needed something else in the meantime. As I looked bemusedly up at the wall of recreational headlamps, I was spotted by a tech savvy young staffer. While he approached he did an assessment of his target, and captioned an old school fossil who hadn't kept up with the modern world (which was accurate). So in response to his offer of help, I remarked I didn't see many items on the wall that appeared to reflect the 2012 status quo in headlamps. He asked me to elaborate on what criteria I was applying (a very good response I thought). I told him that wavelength was my first concern, as most of them seemed to be cool white, and secondly, the emitter, as most again seemed to be either Luxeon or XP-G emitters or even older. He was mometarily taken aback that I knew such big words as 'emitter' and 'wavelength', as words such as 'bulb' and 'color' would have been more age-appropriate. He looked initially perplexed, and I thought I had improved my geekdar ranking. A long baritone expulsion of breath caressed the air around us and shrouded myself and some nearby shoppers in a diaphanous veil of impending erudition. Which then gained substance with the words, "Ah, but you have obviously never encountered this pre-emminent piece of technology that has eclipsed the definition of 'Headlamp'"! A blister pack containing a Petzl NAO appeared in my hands. After cursory inspection, I had to agree that it was somewhat dissimilar to my Petzl with the incandescent 'krypton' bulb, and that evoked a satisfied and knowing nod. It would seem that the allure of this model is in the sensor that makes the emitter reactive. Indeed that does make it unique. But does it in fact make it useful? For that I thought the best way to assess would let the reader be the judge. Hence a matrix comparing the NAO to the closest Spark, which would be the SX5. Click image to load pdf in new window:

Best use scenario...

From an Amazon review:

"The Bad: So the reactive lighting didn't really do it for me. I became frustrated that it just wasn't putting out enough light when I needed it, even with the minimum level set to maximum (using the software). I also found the shifts from brighter to lower outputs in reactive mode to be distracting when moving around quickly in awkward terrain, and the output sometimes just wasn't appropriate for where I was looking. I invariably found myself switching over to the constant mode in favour of any of my preprogrammed reactive mode settings.
The battery level metering does not appear to be based on the battery output, but duration of use between charges, as recorded by electronics within the casing. This means that when you swap a discharged lithium cell out of the plastic battery case, and replace it with a fully charged cell, the battery case will tell you that the fresh battery is low in charge and will even give the flashing warning (emitters pulse 3 times when battery gets low). The light will continue to perform for the expected duration, but you cannot get any indication of the true state of charge. The converse happens when you return an empty cell to the original plastic casing it was charged in. That empty cell will be read as full by the battery meter even though it is not. This is not so smart, but fortunately the meter resets when you next recharge the battery.
Disengaging the battery from the headband cradle could be easier, actually I find it painful as you have to jab the end of your finger into it to force it to release. forget doing this with gloves unless u have a spoon or something on hand. Yes it is secure, but I would have preferred a less painful release mechanism.
The front plastic lens seems extremely vulnerable to scratches and abrasion and does not appear to be replaceable. After the electronics, this is probably the weakest point of the torch.

Ambivalent: Waterproofing: the unit has rubber seals on its assorted removable parts and should display a reasonable level of water resistance to all but prolonged submerges. I know this has disappointed people but this isn't designed to be a dive torch. I am impressed at the way the design team have managed to seal up the usb connection when seated in the headband cradle and I imagine a lot of hours were spent figuring out how to do this. Fortunately it didn't rain on this trip and I didn't submerge the torch, so was not able to test the effectiveness of the waterproofing.

Summary: Despite its short comings, this head torch is a game changer purely based on the software customisation. It produces an excellent light output for all but the more demanding spotlighting applications, and I wouldn't consider it for downhill skiing/snowboarding or mountain bike riding (you will need triple the output of this light).
"

Beamshots on Candlepower forums would collaborate the Amazon review, and show that in reactive mode, the high beam is not as bright as my outdated 200 lumen Princeton Tech Apex with the Luxeon III emitter. (Click for larger images):

Petzl Nao - reactive mode - HIGH:

Princeton Tec Apex 200 – HIGH:

And finaly another observation from a review on Trailspace: "I then checked for interference with my avalanche beacons, and indeed found that close proximity to the beacons introduces a significant amount of noise."