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  1. #1
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    Idea! New Petzl NAO -- Reactive lighting!!

    I know you guys don't really seem to use Petzl for biking (judging from not seeing any posts on them) but I ran across this on another forum and thought it would spark some conversation over here.

    NAO | Petzl

    What do you guys think?

  2. #2
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    Interesting technology with the one sensor actively working to keep you from accidentally blinding your self. I could see it as being of more use on a helmet than a handle bars application. The main question becomes, how efficient is the beam at determining what setting it should be at. For me, going down a mountain single track trail with my light deciding to get brighter or dimmer seems like a disadvantage.

  3. #3
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    I guess they think their end users are too dumb to figure out when to use the LED with the spot lens, LED with the flood len, or combo of both at the various power settings. Seems like an overcomplicated gimmick that makes a light with too many modes slightly more useful if it even works as advertised.

  4. #4
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    ^^^^^^. It appears they do give the user the option of control.

    Quote Originally Posted by Petzl Press Release
    Lighting is controlled via a large rotating on/off switch, which can be locked in the 'off' position. The switch allows the user to choose between Reactive Lighting or Static modes, with high/low output options in each. Static lighting gives a fixed output (non-reactive).

    In Reactive Lighting mode the headset uses a single high-output LED in a wide-angled beam. In Static mode the headset uses both the wide-angled beam and a second high-output LED configured for a focused beam. Maximum power output is 355 lumens. Performance profiles can be customised via Petzl's OS 2.0 on your computer.
    Last edited by cue003; 01-23-2012 at 05:25 PM.

  5. #5
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    My Petzl sits in my backpack for camping, climbing, aplining, rarely used for mtb.

    There are benefits of this feature.
    Sometimes a hands free adjustment is ideal
    Like when you are rapelling off a rock face in the middle of the night or pushing for the summit and you are swinging ice axes with both hands.
    (I've been in these situations).

    Quote Originally Posted by syadasti View Post
    I guess they think their end users are too dumb to figure out when to use the LED with the spot lens, LED with the flood len, or combo of both at the various power settings. Seems like an overcomplicated gimmick that makes a light with too many modes slightly more useful if it even works as advertised.

  6. #6
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    This is my take on this light. Happy to stand corrected. The design of this light is aimed squarely at night orienteering like the 10 Mila - Petzl is very big in events like these. Certainly won't be too useful in MTB. Looking down on the handlebar and it goes dim on you, or as you wave through bushes.

    The ultrasonic sensor or similar, detects like a car reversing ultrasonic sensor. It's useful in night orienteering racing when light intensity is reduced to read the compass, map or running behind competitors to conserve power and reduce useless-wasted-brightness in those situations. It then goes back to higher brightness according to whats in the path of the sensor.

    It'd be great for outdoor adventuring, spelunking or caving, fishing, camping etc

  7. #7
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    I think the "reactive" idea is great as far as walking or jogging goes. Cycling would require a different type of feedback to be more practical. One idea might be to provide a speed indicator that could feed directly to the light(s). Coupled with the ability to program the speed/mode settings this type of Bling might appeal to some who really are in to the "hands free" phenomenon. I could see something like this working really well but I would still want a remote for instant over-ride just in case I wanted to see if that thing walking up the hill is a black cat or a skunk. One problem would still remain though; if you happen to be riding at a speed "just where the circuit trips to change mode", you could end up with the lamp constantly switching back and forth between modes every couple seconds ....which would be a total PITA. Nope, I think I'm keep my manual.

    Now as far as helmet lights go I think the coolest feature to have would be "wireless remote". It would be really cool to be able to control your helmet light without taking your hands off the bar. Yeah, I know someone already has a wireless remote helmet lamp. I'm surprised others haven't decided to copy it yet.

  8. #8
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    Quote Originally Posted by Cat-man-do View Post

    Now as far as helmet lights go I think the coolest feature to have would be "wireless remote". It would be really cool to be able to control your helmet light without taking your hands off the bar. Yeah, I know someone already has a wireless remote helmet lamp. I'm surprised others haven't decided to copy it yet.
    As far as I know the only wireless remote is available from Niteflux - an Aussie light manufacturer. Would love a remote for the MJ-880 - currently the switching is not optimum.

  9. #9
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    I can see the benefit in other applications: climbing, hiking etc. but the speeds in these sports are much lower and you can stop immediately if the light misbehaves but for the higher speeds of offroad riding I see it as a liability.
    If you need me I'll be at the bar

  10. #10
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    Quote Originally Posted by Cat-man-do View Post

    Now as far as helmet lights go I think the coolest feature to have would be "wireless remote". It would be really cool to be able to control your helmet light without taking your hands off the bar. Yeah, I know someone already has a wireless remote helmet lamp. I'm surprised others haven't decided to copy it yet.
    As far as I know the only wireless remote is available from Niteflux - an Aussie light manufacturer. Would love a remote for the MJ-880 - currently the switching is not optimum.

  11. #11
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    it would be a good light for night fishing or camping where in one moment you can be in the tent, the next by the fire, or in the woods. i don't think riding.

  12. #12
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    I actually think this could be one of the most important advances in the future (say: next 10 years), but of course, it needs much more development.

    I can see a proximity unit similar to what is available in cameras: that sense a large area in front of them and set the focus accordingly. Now in the case of bike lamps the "focus" will be replaced by brightness. Eg. the light could set the brightness across a given area according to the distance of the object sensed.

    So, for example, if you have 9 leds/lenses that you can control individually, you can lay them out in a 3x3 pattern, each covering 1/9th of the beam. The lower row would be responsible for close-range lighting (in front of the bike), the middle for mid-range, and the upper for distance.

    Actually there is already a light with a similar setup, the L&M Seca has its bottom 3 leds responsible for the close range. Of course, these are not individually controlled, and there is no proximity sensor there, but still...

    Building such a lighthead today would cost a fortune, but I do think it is very much possible. Technology exists, even if not cheap, and not at this scale. But hey, my phone's processor and memory exceeds what I had in my PC just 10-15 years ago...

    Bottom line is, I'm actually quite happy that it seems like I'm going to be able to spend a lot of money on lights in the future... ;-)

  13. #13
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    It still seems like a gimmick. Its better to have consistent light levels as your eye adjusts to light levels gradually so changing the light levels on the fly frequently and rapidly could actually be worse for the user. Its more complicated than Petzl marketing would lead you to believe or LED color though:

    Night Vision - The Red Myth

    It takes a while for true night vision to be recovered. About 10 minutes for 10%, 30-45 minutes for 80%, the rest may take hours, days, or a week. The issue is the chemical in the eye, rhodopsin - commonly called visual purple, is broken down quickly by light. The main issue then is intensity; color is only an issue because the rods (responsible for night vision) are most sensitive at a particular color. That color is a blue-green (507nm) similar to traffic light green (which is this color for a entirely different reason). It would seem that using the lowest brightness (using this color) additional light needed for a task is the best bet to retain this dark adaptation because it allows rods to function at their best.
    Conclusions:

    No matter what your color choice it must be fully adjustable for intensity.
    If you need the fastest dark adaptation recovery and can adjust to the limitations, or everyone in your group is using night vision equipment then blue-green.
    If you must see detail (reading a star chart, or instrument settings) and can lose peripheral vision (see note 1), then a very long wavelength red at a very low level. Red really only has an advantage at very low levels (were the night blind spot is very obvious).
    A general walking around light so that you don't trip over the tripod, knock over equipment or bump into people, then blue-green with enough red added to get rid of the night blind spot, or maybe just use white. Blue-green at higher brightness also works very well and at a lower intensity than white.
    If you need to see color and detail then likely the best choice is the dimmest white light for the shortest amount of time.
    If you are in the military you must follow their rules; hopefully they will have a good course in unassisted night vision.
    If you are a pilot and say you only fly in the day, you should be aware of the problems of night vision and should consider a basic (ground) course in night flying.
    If you wonder why no one else has drawn these conclusions look at the dashboard of most cars. The markings are large, the pointers are large and an orange-red (a compromise, for certain "color blind" persons) and at night it is edge lit with blue-green filtered fully intensity adjustable light.

    For Best night vision:

    Be sure you are getting enough vitamin A or its precursor beta-carotene in your diet (needed for the visual purple).
    Green leafy stuff is best followed by vegetables that have an orange color. Yes that includes carrots but spinach or dark leaf lettuce are better. It is possible to get too much vitamin A especially as a supplement.
    Keep up your general health. Smoking is also very bad for night vision, as are most illegal drugs and some prescription drugs.
    Keep you blood sugar level as even as possible. No meal skipping. Six small meals are better than three large meals. For carbohydrates favor starches (potatoes, rice,and bread) over simple sugars (sweets, alcohol).
    Use dark neutral gray sunglasses, that pass no more that 15% in full sun, when outside during the day.
    Random google result which also describes it, it would be great if a bike light company took a more indepth look when designing their light:

    LEDs Magazine - WEB EXCLUSIVE: Safety-centered approach improves quality of light for petrochemical facilities

    It is important to realise that light is not simply light, as it is being interpreted by a very complex human visual system. The retina, a light-sensitive screen at the back of the eye, has many light receptors that convert light into electrified signals sent to the vision centres of the brain. Because of their shapes the two major categories of light receptors are called cones and rods. The sensitivity of the human eye varies at different light levels and, while cones are responsible for day vision, rods play an important role in night-time vision.

    The very central part of the retina, the fovea, contains only cones while the rest of the retina contains both rods and cones. Cones are active at high light levels and are most densely situated in the central part of the field of view, so when we look directly at an object, we are using our cone receptors.

    The rods are responsible for human vision at low light levels, and are prevalent in the peripheral field of view, away from our direct line of sight. As shown in Fig. 2 the spectral response of the cones corresponds to the photopic V(λ) sensitivity curve. As the light levels decrease, the cones become less active, the rods become active and spectral sensitivity gradually switches towards the scotopic response curve.

    The spectral sensitivity of the human eye at photopic light levels (day vision) has a maximum wavelength of 555nm as described by the International Commission on Illumination (CIE). At scotopic light levels this value is located at a lower wavelength of 507nm. Both in theory and in practice, the determination of lamp lumens involves knowing the spectral power distribution (SPD) of the lamp and the visual response of the eye.

    Vision scientists have known for most of the twentieth century that in fact the way the eye responds to color is dependent upon the lighting conditions. While it’s widely accepted that cones handle day vision and rods are designed for night vision, up until now lighting manufacturers measuring a lamp’s lumen output have continued to utilise light meters that are calibrated to the eye’s sensitivity to only cone-activated vision (photopic), completely ignoring the effect of rod-activated vision (scotopic). Unfortunately this represents a gross oversimplification of human vision.

    This problem is further compounded by the realisation that the V(λ) curve was established from research conducted using the fovea, the central ±1°of the eye’s field of view, while central human vision is at least ±10°. So, if the visual task is off-centre and at a low level of luminance, the fundamental definition of the lumen would not be accurate.

    B. Color
    In the past it has been widely accepted that under virtually all circumstances where artificial light is used, lighting level calculations could ignore light source color. When calculating such levels in practical design situations, results are based on the lamp’s lumen rating, usually provided by the manufacturer. Calculated values of candelas, lumens, lux or cd/m2 are not dependent upon whether the light source is white, bluish white, yellow or pink.

    Research and publications indicating the importance of lamp spectral distribution have been available for many years. Recently, some lighting experts have started to use the term “effective lumens” to define the modified lumen output of a lamp, taking into account the shifting color sensitivity of the eye at low light levels.

    For example, HPS lamps have high lumen ratings based on the definition that the lumen is the amount of light as perceived by the eye under photopic conditions. It is not so much that the sodium lamp produces a high output of energy, but rather that its energy peak is near the maximum photopic sensitivity wavelength of the eye (see yellow region in Figure 3). However, because very little energy output of the HPS lamp occurs at wavelengths shorter than the peak, so the effective lumens for scotopic conditions (the V'(λ) curve in Fig. 2) is greatly reduced. Sodium produces very little blue and green light, and therefore its effectiveness under low light levels is drastically reduced. In other words at night, when the light has a true purpose in providing area illumination, the quality of HPS source is rather poor due to very low “effective lumens”.

    In contrast if we consider a white light source (for example white LED) with some balanced energy peaks (or even with peaks predominantly in the blue/green regions) it will be seen that the energy output aligns more closely with the peak of the scotopic eye sensitivity curve. The net result is that the effective lumens increase as the light level reduces at night and the eye shifts to a blue/green peak sensitivity.

    In summary, under mesopic viewing conditions, yellow sources have reduced effectiveness while blue/green sources have increased effectiveness. We therefore propose the concept of a ratio for determining the true rating of a fixture’s illumination in relation to lumens utilised by the human eye. This could provide a mechanism to determine the true “quality of light,” hence the term quality of light factor (QLF).

    From the above discussion it is clear that the strength of the scotopic eye sensitivity of an LED is a number of times higher than that of an HPS source. Therefore the QLF of an LED source should be greater than the QLF of an HPS source and this factor should be rated high while purchasing Safety Lights.
    Last edited by syadasti; 01-25-2012 at 08:55 AM.

  14. #14
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    It is kind of fun to think about the possibilities though, for example if you added a gps chip to the light and had the brightness scale based on the speed that you were traveling. It would be kind of nice to have it know when you were climbing and use a preset level and then have it ramp up to a set speed above which it is always on at 100%. The gps receiver would cut into battery life, but in a perfect world there is some room for a smarter lighting system than on off and a series of preset levels.

  15. #15
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    Quote Originally Posted by OpenLight View Post
    It is kind of fun to think about the possibilities though, for example if you added a gps chip to the light and had the brightness scale based on the speed that you were traveling. It would be kind of nice to have it know when you were climbing and use a preset level and then have it ramp up to a set speed above which it is always on at 100%. The gps receiver would cut into battery life, but in a perfect world there is some room for a smarter lighting system than on off and a series of preset levels.
    Realistically I don't think the talent or R&D budget is out there for properly designed commercial solution. Eventual spin-off technology from other industries is more likely.

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