Red Light for Land Nav

Hello!

Basically I need a strong red light.

I am a contracted ROTC Cadet at my university and am looking for a red light for night time land navigation.
This past week end I went on the hardest land nav course I've been on and will soon be going to LDAC so I
want to find a good light that will make finding points easier.

The points I will be looking for are small pieces of plywood with no reflective surfaces in thick brush. The course
is also timed so it's important that I find these points as soon as I get to them.

I've done some searching on the forums and did find this post http://www.candlepowerforums.com/vb/showthread.php?248819-Red-Light-Headlamps

I looked into Zerbra H501r (which utilizes red LEDs) and the Eagle Tac T20C2 with the red filter.

It's my understanding that red LEDs are able to cast light further than a light with a red filter (I could be wrong)

I'm mainly wondering if anyone has had experience with both of these lights and how they like them, or for recommendations for better lights.

I'm a complete noob when it comes to flashlights so don't rag on me too hard D: (been using the same $15 walmart headlamp with the 2 LEDs for the past couple years)

Thank you!

First off, Welcome to CPF!

Red light for land nav...well, first, let's clear the ???'s about the LED casting light further, etc. Think about it this way; Red filters don't turn the light red, they block out any light that isn't red...so, LED's don't work too good with filters, since they emit very little light in the red spectrum. You will still be able to see the light etc., but alot of it get's blocked. If you want to stay with an LED, then you'll need to switch to a light with a red emitter (which for LED's is usaully limited to the 5mm ones'. Yer recommendations will be based on how much you're willing to spend. Some recommendations form high to low ($ wise) include the Surefire Kroma (which has a VERY bright high red, and a low red for up close nav), or the First light tomahawk. I'd also recommend the SF L1, but they are very hard to find. This would be perfect due to how far the light throws. Or an Inova X5 in red for a little cheaper. The two Surefires mentioned would be the best since they so easily switch between a high and low red, instead of being stuck with a constant high red. But then, it's all up to how much you're looking to spend. Some of these lights can be had for a relatively decent price on the MP.

Incans are the best for "cheap" "throwy red's", since they emit almost entirely in the red spectrum, so alot of light makes it out the filter. If weight wasn't an issue a 3D/3C Maglite with a red filter would throw plenty...this could be used in conjunction with a red head lamp, so you can conserve battery power. Or a Surefire G2/6P with a red filter if the mag would be too heavy.

Hope this helps you out some, and let us know if you have any more questions.

Eagle Tac T20C2 with the red filter.

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EagleTac make red LED drop-ins for the P20 / T20. As AoW says, these will give you a lot more output than a white LED with a red filter in front of it.

I use an EagleTac P20C2 with the red LED drop-in. This gives you two levels, and on high throws quite well. The Kroma is much more expensive and more of a flood - very good for close-up, but the EagleTac dropin will throw much further.

I highly recommend a Streamlight Night Com LED flashlight @ $41.95.

I keep 1 @ my bedside and use it nightly, when needed (I have had it approx. 1 year). I also have a SF L1 (red) and multiple Inova X-5's (red), but the 1 that I use, is the Night Com.

It has a rotating switch that makes sure that when placed in RED mode, ONLY the Red LED's will work. It can also be placed in a safe mode, where it can not light, even when it's tail button is pushed. In white mode it has a white LED @ approx. 100 lms. I think it would be perfect for what you seek.

My .02 FWIW YMMV

Are there other concerns with this light? That is, does your searching during the land-nav course need to be covert? Many of us routinely carry lights that are visible for the best part of a mile, and much further if someone is directly downrange of the beam. My experience with red LEDs is that they offer poor color rendition - much worse than red-filtered incandescent light. This makes it dangerous for me to try to move quickly using red light - I can't tell dry floors from wet, or puddles from holes. This may be an irregularity of my own eyes.

I think we can help more if we know:

* The light levels on the course
* The light you use and what it does right for you
* What you want more of
* Budget
* Runtime needs

You describe a headlamp - hands-free lighting is great for searching and crawling through brush, but has some weaknesses - lights near your eyes hide shadows that give depth to the ground you're tripping over.

Edit: Double Post?

Olight makes a nice one, OLIGHT-M20-CRIMSON. The M20's are classics, solid, well executed. Good luck with the land-nav. Theres nothing sadder than a lost Lt.

Kwanon;

Does the M20 crimson have high/medium/low settings or is it full blast only ?

M20 crimson, 105 lumens, 2.3 hours, one level. :thumbsup:

Anefyd said:

Hello!

Basically I need a strong red light.

I am a contracted ROTC Cadet at my university and am looking for a red light for night time land navigation.
This past week end I went on the hardest land nav course I've been on and will soon be going to LDAC so I
want to find a good light that will make finding points easier.

The points I will be looking for are small pieces of plywood with no reflective surfaces in thick brush. The course
is also timed so it's important that I find these points as soon as I get to them.

I've done some searching on the forums and did find this post http://www.candlepowerforums.com/vb/showthread.php?248819-Red-Light-Headlamps

I looked into Zerbra H501r (which utilizes red LEDs) and the Eagle Tac T20C2 with the red filter.

Click to expand...

Are you trying to spot these things at some range, or are you close to them when you start? There are two models of zebralight H51 - the H51r and H51Fr, depending on whether you need to spot things at a distand, or if you need more of a floodlight. (The "Fr" model is floody.) They also make H31r and H31Fr, which are CR123 versions of the light. (The 51 models are AA powered.)

Out of curiosity, why a red light, rather than a bright white light - do you have to minimize your own visibility or something, or is it to maintain dark adaptation? (I'm sorry, I'm sure that is a stupid question.) I use one of the Zebralight H51r's to help maintain dark adaptation, but I mostly use it for astronomy.

I have the H31R and this thing is blinding bright and the throw is really amazing, especially for the size (beats any light I've tried with a red filter in both intensity and throw). Totally worth it IMO.

I too am curious as to why it has to be a red light?? Color handicap?

Cataract said:

I too am curious as to why it has to be a red light?? Color handicap?

Click to expand...

I think it is mainly superstition. A 1-watt red LED will ruin night vision quite effectively, but maybe it preserves sensitivity to other colors. Ask any astronomer star party - they'll say NO RED LIIIIIIIIGHTS, but I could take my 14W red traffic light panels (I have 4) and ruin their fun with pure red. From the next block.

My theory is, human eyes are less sensitive to red lights, and when all light came from white-hot filaments you'd put a red filter on to patch things up to be darker. Now that pure-red sources are available in pocket-size with ludicrous brightness, people still think that using red LED is super stealthy. Some of my friends use their red LED lights to be 'uber ninjas,' but they use them wrong. The ONLY tactical/stealth light is the one that is used covertly, rarely, and below line of sight of anyone interested in seeing you. And if you are trying to hide use of light, you'd better use the minimum you can. NOW you're more interested in having lights that blend in (Orange-yellow around HPS, etc) than a Red Ninja Lite (TM). Dim & pointed down = king of stealth, all else follows.

If you've decided you want RED for land nav be advised that the vast majority of lights sold as red are not red at all. Most lights sold as red are actually red/orange at around ~630nm. True red LEDs are in the 640-660nm range.

Any light at 630nm will negatively affect cones, which is exactly the opposite of what most wanted when they bought lights they were told were red. If you want the benefits of red lights on scotopic vision the light will really have to be red. Rigel is the only manufacturer of lights with 640-660nm LEDs that I am aware of.

The Original Rigel model would probably be better suited to outdoor use than the newer Mini.

Absolutely correct. I have a stock of 660nm LEDs to swap out for the usual orangey offerings.

AnAppleSnail said:

I think it is mainly superstition. A 1-watt red LED will ruin night vision quite effectively, but maybe it preserves sensitivity to other colors. Ask any astronomer star party - they'll say NO RED LIIIIIIIIGHTS, but I could take my 14W red traffic light panels (I have 4) and ruin their fun with pure red. From the next block.

My theory is, human eyes are less sensitive to red lights, and when all light came from white-hot filaments you'd put a red filter on to patch things up to be darker.

Click to expand...

I think this comes from a couple of things:
1: Our eyes really are less senstive to red light, and I find that my dark adaptation is less affected, and returns more quickly with dim red light than dim white light. Possibly this is because it is hard to get dim enough white light, because most lights are just way too bright.
2: Back in the old days, you'd use red light for developing film, so people doing astro photography at star parties wouldn't get their exposures ruined if people used red lights. Of course in these days of CCD imagers, red light is exactly the wrong color to use for this reason...

But yes, too much red light still ruins your dark adaption - a red filtered car headlight will still ruin everyone's night, or at least the next 30-45 minutes of it...

MrBenchmark said:

. . . . I find that my dark adaptation is less affected, and returns more quickly with dim red light than dim white light. . . . . . .

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That's because if you compare the sensitivity of Photopic Vision to Scotopic vision, that RATIO is largest at the Red end of the spectrum. i.e. Red will cause less leaching of the photochemicals in the Rods used for the Scotopic vision.

So IF you need to use Photopic vision to see at high resolution e.g. to read AND you want to be able to quickly change to Scotopic Vision to see at Starlight levels, then you are best off using Red light.

If not, you may as well use dim white light - unless the piece of plywood lights up brighter in Red than the surrounding green vegetation which will appear black.

If you have colleagues nearby using Night Vision Goggles - or enemies searching for you using NVG, Red is the WORST colour to use.

Thank you for all of the recommendations.

I apologize for the double post at first I was thinking I posted in the wrong forum and was trying to get the other one deleted.

Light Levels- Light levels on the course is dependant on the brightness of the moon. It's fine walking on roads and trails and what not with my dinky head lamp, but when I'm actually searching for the points themselves I have to cut off into thick brush where it's pitch black.

Light I'm Using- I am currently using this "cheapo" Walmart headlamp http://www.walmart.com/ip/Energizer-...light/10233058. My issue with it is that there's zero flood and it throws all of 5 meters in front of me.

What I Want- Basically I want an all around better light than what I'm currently using, a handheld would be nice, I do still plan to use my current headlamp for plotting points, walking roads, taking azimuths, etc...

Budget- I'm willing to spend up to $100, I'm willing to pay quite a bit more if you guys think I'll need to though.

Runtime Needs- Since I'll be using the headlamp while I'm walking trails I'll realistically only need about a 2 hour run time while I'm fumbling through the brush, but more is always good.

Battery Preference- This doesn't really matter to me whatever type is easiest to deal with I suppose.

Flood vs. Throw- I'm leaning more toward flood.


For FTX and LDAC we can only use red light. I asked my cadre and there is no lumen restrictions it just needs to be red. If we were allowed to use white light I would light up the whole damn jungle!

I'm really liking the Olight M2 Crimson from what I've been reading/watching on Youtube and I'm also liking the EagleTac T20C2 because of the versatility. (I like the additional little trinkets, who doesn't love a glow in the dark tailcap )

Thanks again for all the answers guys, I may have to add a lights to my knife collection.

One more question, are you guys totally against using red filters over red native LEDs?


One more thing! Concerning distances
The furthest I had to walk into brush was a point that was in a gulch 200m off the road through some pretty thick brush.
I was able to navigate to within 20m of that point (usually I'm able to get with in 10-20m of my points), but it still took me a good 15-20 minutes just to find it.

red filters over LEDS are just terrible. You'll be better off with a red LED. The reason is that white LEDs are actually blue LEDs surrounded by a phosphor that glows over a wider spectrum of light. Because of this, they don't tend to produce as much red light as an incandescent, which actually produces a significant portion of its output in the red part of the spectrum.

I think you will like the floody version of the zebralight.

Yeah I'm thinking at this point it's in between the Zebralight H51fr and the T20C2 with the red LED drop-in.

I'm leaning a little more toward the T20 since I can mount it on my AR.

Anefyd said:

. . . . For FTX and LDAC we can only use red light. I asked my cadre and there is no lumen restrictions it just needs to be red. If we were allowed to use white light I would light up the whole damn jungle! . . . . .

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So the assumption is that 100 lumens of Red light will be less detectable than 10 lumens of White light ????

From what my CSM told me it doesn't matter how bright it is or rather or not they can see me fumbling through the brush, it just needs to be red. (It doesn't make sense to me either, but oh well.)