# The thinking behind the Zebra H31r and H51r RED Headlamps?



## Bolster (Jun 29, 2011)

I'm scratching my head over the release of the H31r and the H51r. After scouring the USA vendors and finding not a single H501r for sale, I was thrilled to hear of a RED release from Zebra. I need one for astronomy outings. But the release appear to be lamps with bright hotspots. So...who do these appeal to? And for what purpose? 

My thinking is that red light has the primary purpose of night vision protection, number one use being for reading of maps and charts, and looking for nearby gear. Or for hiking a trail at night. For these purposes I'd want a soft floody light, right? Why would I want a red light, much of it concentrated into a 9-degree hotspot? And what's the purpose of 100 lumen in red? I don't understand. I'd think the sublumen modes would be most useful. 

It seems that the desire for flood would be especially the case for a red headlamp. The currently running poll shows that pure flood is the most preferred category for beam type (for headlamps), followed by a directional flood. Either of these would seem to be ideal for a red headlight. So, explain this to me, please. There must be a reason for the brilliant spot red headlamp. Someone must be buying these for some purpose!


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## B0wz3r (Jun 29, 2011)

Why not for signaling or emergency use? They have a flashy mode, don't they? Or how about as a bicycle tail light? I'm sure there are plenty of other uses that I'm just too brain-dead to think of right now...


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## Bolster (Jun 29, 2011)

Rephrase question: What target market are they aiming for? 

Signaling came to mind, but why a headlamp for that? I think a tail light would be better served with a wide angle of view so placement and alignment wasn't critical. Not so easy to be certain the driver on the road is in your 9-degree beam.

I hope Zebralight will consider designing a red light with a wide beam or flood...and lotsa low levels...


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## cave dave (Jun 29, 2011)

If they don't offer a frosted lens version soon, head over to the marketplace for some DC-Fix and diffuse it yourself, that is my plan.

I'd prefer an H501r pure flood as well but they are hard to come by. My intended use is bicycle rear flasher and I would also prefer if they offered a 2hz strobe and a dimmer strobe options for bicycle use. At 100lm and 4 hz the battery just won't last very long.


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## carrot (Jun 29, 2011)

I don't see why Zebralight can't make a white AND red headlamp. Their UI is obviously already suited for it.


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## B0wz3r (Jun 29, 2011)

Bolster said:


> Rephrase question: What target market are they aiming for?
> 
> Signaling came to mind, but why a headlamp for that? I think a tail light would be better served with a wide angle of view so placement and alignment wasn't critical. Not so easy to be certain the driver on the road is in your 9-degree beam.


 
Good questions... unfortunately, I'll be damned if I know...  

I was looking at them a little while ago, and I think I'll pick one up for my wife for astronomy. Unfortunately their advertised wavelength is still red/orange, and not a true deep red.


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## gcbryan (Jun 30, 2011)

carrot said:


> I don't see why Zebralight can't make a white AND red headlamp. Their UI is obviously already suited for it.


 
Probably for the same reason they don't offer a flood and spot lamp. It's either because they sell more lights the other way or because they just don't want to


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## B0wz3r (Jul 1, 2011)

Upon further reflection, I'm going to pass on one (or any) of these, unfortunately. They're not true deep red.


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## Bolster (Jul 1, 2011)

Is deep red better for night adaptation, or is there another advantage of deep red over orange-red?


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## B0wz3r (Jul 2, 2011)

Bolster said:


> Is deep red better for night adaptation, or is there another advantage of deep red over orange-red?


 
Red-orange is about 620 - 630 nm; still well within the long wavelength (red) cones' ability to respond. 670 - 680 nm is the very upper range of their response ability, and the border between visual red and IR. At this wavelength, the red cones respond a little, but not usually enough to invoke light adaptation, as long as the light isn't bright enough.


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## Bolster (Jul 2, 2011)

...so...the higher/longer wavelength (closer to infared), the better for retaining night vision. Right?


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## B0wz3r (Jul 2, 2011)

Bolster said:


> ...so...the higher/shorter wavelength (closer to infared), the better for retaining night vision. Right?


 
Yes. Longer wavelengths actually; 670 is a longer wavelength than 630. You can go too far though, because eventually you'll get into IR and we can't see that too well. And, IIRC, IR is a form of heat, so at high levels of intensity you can actually suffer damage from it. 675 is about the upper limit of what we can actually see. 365 nm is about the lower limit; below that and you're getting into UV which is what causes sunburn and skin cancer and the like.


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## Bolster (Jul 2, 2011)

D'oh, corrected. Nifty to know this. Thanks for the education!

Think of all the colors that exist, that we can't see in our narrow range...

Anyway, your comments have me scratching my head even harder over Z's release of these reds...what are they for, then?


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## B0wz3r (Jul 2, 2011)

Bolster said:


> D'oh, corrected. Nifty to know this. Thanks for the education!
> 
> Think of all the colors that exist, that we can't see in our narrow range...
> 
> Anyway, your comments have me scratching my head even harder over Z's release of these reds...what are they for, then?


 
I think it's just because they want to provide a product that's comparable to what other manufacturers have available that's targeted at the night vision segment of the market. As I've discussed before on here, even the amateur astronomy crowd's choice of NV lights are based as much on tradition and anecdote rather than genuine scientific knowledge of the topic. I prefer the night vision green (turquoise actually) lights for such uses, as they work far better for me than red-orange. (I have yet to find a genuine deep-red night vision light actually. Once I do, I will buy one.) For the time being, I'm trying to find some #29 deep red photography gels to use with my new L2r once I get a drop-in module for it.


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## pblanch (Jul 2, 2011)

Bolster said:


> Why would I want a red light, much of it concentrated into a 9-degree hotspot? And what's the purpose of 100 lumen in red? I don't understand. I'd think the sublumen modes would be most useful.



The more I think about it, the more sense it makes. I was hanging out to see the H502 come in red but doesn't look like it going to happen and the thing holding me back from the H51/31r is that I already have a H51 and couldn't think of anything worse than reaching for the wrong one. But having the red hot spot and not seeing anything else. Makes a lot of sense too me. Looks like that/s one ZL I am not going to get. Dont worry there is still plenty others on the list.


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## Offroad'Bent (Jul 15, 2011)

Bike tail light visible in daylight?


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## Mdinana (Jul 16, 2011)

I just got mine a couple days ago. The low is pretty useful, even if it is a bit of a hotspot; the low/alternate is uber-low. Like, look at the LED and think "Wow, you can see the filaments" low. Almost too low unless you're truly in a light free environment (probably OK in a cave) It's got a decent beam though. The white LED is a similar throw and beam to my Novatac Storm; the Red is probably similar but obviously doesn't cast as far (I'll try it out tonight for distance)


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## GoingGear.com (Jul 17, 2011)

I don't know what their intended purpose was, but I had a couple of customers tell me that they were great for reading. One guy used his at night in bed and his wife was not bothered by the red light while she was by white. Another guy said that white/neutral/warm lights kept him awake while reading while red would help make him sleepy and more likely to go to bed. 

No clue how universal any of that is, although I will say that when I use a red light at night when I inevitably go to bed later than my wife, she never wakes up. White does bother her. 

I actually also really like red in the woods. When you just need a tiny bit of light, like for up close tasks or in the tent/hammock, red is a lot less harsh than even very >1 lumen white. I like red for outdoors stuff. 

As far as popularity, the H501r is the least popular Zebralight that I have seen. Time will tell about the H51r.


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## Bolster (Jul 17, 2011)

Thanks for posting, GoingGear. Nice to have a dealer's perspective. If you have a spare "unpopular" H501r left over, I'm your customer for it...


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## Inliner (Jul 17, 2011)

Bolster, sent you a PM a few days back.


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## Bolster (Jul 17, 2011)

PM your way Inliner.


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## StandardBattery (Jul 17, 2011)

Hi don't know if they had an intended market or customer for these, but my initial impressions are good. I really like them and I'm surprised by how bright they are, as well as how low the lowest low is. I'm going to try to compare to the H501r at some point. Was thinking if I wanted to try some diffusion film on it. I have found it works good at night with the lights out to ballance the bright computer screen in a darrk room... the red is good enough and I don't need to turn on a small light. Have to keep the light away from directly illuminating the screen though, that just make it look ugly and has a very bad refelection. I'm thinking with diffusion it would be good for Kindle reading at night.


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## B0wz3r (Jul 18, 2011)

Just an FYI, there is a red LED flashlights thread over in the flashlights section if anyone wants to check it out. I posted a lot there on night vision issues, and the differences between red-orange and true deep red, and night-vision green tints.

Sorry, I'm too lazy to search for and copy the link right now. I'll get it for you guys later.


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## privard (Sep 3, 2011)

Bolster said:


> I'm scratching my head over the release of the H31r and the H51r. ... So...who do these appeal to? And for what purpose?



I use mine on low-medium for hiking in woods (high-medium if it's a brighter night). Great for walking down a dark trail without breaking my leg, and impact on night vision is a lot less than a white light. Also I can fire it up to high to see something a little farther away, again without nearly the penalty a white light would have on my dark vision--I generally walk at night without a light on and just turn it on briefly for especially dark stretches under tree cover or if there's no moon at all, so maintaining my dark adaptation is important to me. 675 nm is better for night vision--but it's so close to the limit of human visibility that it'd have to be incredibly bright to be of any use for walking on uneven terrain. My H51r is a great compromise between having enough light and maintaining my night vision. I also use it on the low modes for night photograpy and astrophotography--the lowest for basic dial and knob settings if it's really dark, the "high" low for reading LCD screens when I have to. "Low" low has no noticeable affect on my dark vision (it's VERY low); "high" low only a slight affect that my dark-adapted vision recovers from pretty quickly. 

So scratch no longer--maybe it doesn't work for you, but it does for me and for at least enough other people to make it worthwhile for Zebralight to keep making these things.

And if you can't find an H50r-style light that's wide and diffuse enough for you, sticking something over the lens of an H51r or H31r takes only a few seconds (hint: saran wrap is a cheap and easy way to keep anything in place; just keep as much of the head uncovered as possible for cooling if you plan to use high modes).


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## Yogazoo (Sep 15, 2012)

The h51r in this video http://youtu.be/Ca--dvX8F8s appears to have a bit of sidespill unless the camera is adding to the effect. I personally only use red light for getting into my favorite hunting spot. Large ungulates have greater difficulty seeing red light and it's not as intrusive. I think the H51r is just the light (headlamp) I've been looking for. Most red LED's on the current crop of headlamps are an afterthought (extremely dim).


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## Pacecar (Sep 21, 2012)

A "brilliant spot red headlamp" is useful for racoon and coyote hunting. The eyes of those animals are somewhat colorblind to the red spectrum, yet their eyes highly reflect the red light to make it easier to detect the animal.


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