The Nightsword project

[get-lit]

LOL! Thanks BVH, that's easy to say from someone that had a 60" carbon arc! I want this to be something that won't be awkward to carry around.

I've re-uploaded the drawings, this time with 11.25" total diameter from 11", for an additional 4.6% more power. Anything larger ventures into awkward size territory, and if I were to make the total diameter 11.5", the power gain for that additional 1/4" is adds only another 2.3%, which is diminished from the 4.6% when going from 11" to 11.25". I'm happy 11.25".

[Lips]

Just had a hospital helicopter go over the house with his spotlight on for landing, thought about a Nightsword hanging out the door


Wondering are you going for the commercial market (patents) or just flashaholics like in the beginning? The light looks fantastic, hope you license or sell it and make some money! I have a friend developing a product and going thru patent process, he's had a hard time without proper funding. He got investors involved and they are constantly calling pushing for results...

Any idea of selling cost range in mind yet? Curious what expertise background you have to design such a light.

Keep Plugging!

[get-lit]

Great questions... Although my primary goal is to get these in the hands of myself and fellow CPFers, there are some things I may consider patenting for later. I'll be offering them at my cost and I'm doing my best to keep it down, but this is not designed to be cost effective because I'm not appealing to any commercial market, so I'm not compromising anything for cost. For instance I could easily save money by compromising some weight and bulk for less expensive materials than carbon fiber and Kevlar, or I could choose 18-8 stainless steel for the internal metal components because they won't get wet, but I want this to be something that truly lasts even in hot and humid conditions, so I'm using all 316. I could use standard type connectors, wires, and switch, DC converter, etc, but I'm going with mil-spec. These material and component choices cost double, and many of them double again since I'm not buying in mass quantity I have to pay retail. I could also go with a low grade reflector that's less reflective, less accurate, and less durable and save a ton of money. When I consider the hard cost of the major components, the lamp and ballast, and reflector alone, this is already stupid expensive, so I feel that not compromising on the other components and materials is a marginal increase relative to those hard costs.

I have no idea on total cost as of yet because I'm waiting for the quote for the primary reflector, I don't know how much carbon fiber and Kevlar material I'll be consuming, and I don't yet know the tooling costs for producing the bezel and internal mounts, ducting, and EDPM gaskets, ceramic exhaust, among a some other components. I wish I could give a figure but at this point I don't know.

I'm very thankful to BVH for his free help, I'm putting it to use and that savings goes directly to others.

As far as my background, I'm a programmer by trade going on 18 years. I'm basically driven to thoroughly understand how things work. The more complex and challenging, the more interested I become. My work as a programmer conditioned me to use a methodical functional approach to accomplishing things which I initially have no idea how to. I've developed a knack for unraveling tasks with that approach, where I'd explore what needs to be done to accomplish something and all of the possible solutions and make pragmatic choices based strictly upon calculable considerations.

This was supposed to be done many years ago, I actually had an interest in the early 90's and began diving into it into in the later 90's, but I kept finding myself in over my head and refused to not give up and kept going at it. Through the process, I've learned and applied things I never even realized existed until I needed to know them, including material properties such as tensile, compressive, impact, and modulus of strengths and elasticities.. thermal expansion, thermal resistance and conductance, electrical resistance and conductance, breakdown voltage of materials and air relative to temperature, pressure, and humidity... material light reflectance and transmittance relative to incident angle and wavelength... flow, pressure, surface friction, screw design standards, ozone resistance, UV resistance, temperature resistance, electromagnetic emission and its absorption, reflectance, interference... ingress protection standards, mil-spec standards, UL standards, the light spectrum and human sensitivity to it, air filter materials, and the micron filtering benefit of pores per inch and material thickness versus air flow resistance, short arc lamp design and construction, shot arc luminous intensity profiles and luminous distribution profiles, short arc ballast design and construction principals, product design and construction, and molding and fabrication processes.

When it comes to optics alone, I had to thoroughly understand the geometry of the beam, from the light source all the way through to the illuminated object at distance. In order to make calculable optic design decisions, there were no useful tools available, so I developed the beam calculator from the ground up. It all took years of regular headache sessions. I eventually realized that when I'd get frustrated and thought I'd never understand something or figure out a solution, patience was always the answer. Everything always worked itself out if I just relaxed and gave it time.

[BVH]

Get lit, thanks for all the good info above. No bits yesterday so maybe Monday.

[get-lit]

Ya I sent them regular postage, plus it's the holidays.

[BVH]

Well, to warm up my equipment for its' Nightsword efforts, I used the lathe and mill yesterday and today on a funky project but I think the final "product" will perform quite well. Once done, I'll start one of my usual threads on it.

[Patriot]

Thanks Get-lit for sharing your passion with us. Thanks BVH for volunteering your skills to help push the project forward. It's really neat to be able to follow this amazing collaboration of ingenuity and technology. Nothing like this has every existed before!

[get-lit]

Happy New Year! I've narrowed the depth of the bezel considerably to save weight and bring the heavy lens closer to the center of gravity. The tip of the thumb is literally just 2-1/4" from the lens, and the lens is also centered on the lamp focal point. This thing could not possibly get any more compact. The housing is taking on the true form of the long FL reflector within it. The lamp anode actually extends all of the way to the front end of the exhaust vent, which is why the vent must be so long. Drawings updated. And thanks guys for the support!

Edit.. The compromise to this more compact configuration is that the middle section of the focus range will have a portion of spill light, in which the lamp source could be visible from the side forward of the light. Many lights do this, but it's not something you'd want to look at, so it will have to be something to be aware of halfway through the focus range.

[get-lit]

In BVH's recent post, he realized a phenomenon of the beam which he questioned, and it reminded me of a topic I wanted to discuss that is very important because few people realize that candlepower alone does not determine overall beam power in the air nor on target.

Imagine if you will, a highly collimated tiny amount of light, say for instance a 5mw laser so collimated it produces 100 MCP (100 Million Candle Power). Let's also say you have a light that's 20 MCP with 10,000 Lumen in the beam. Say that 5mw laser is a green laser at 555nm (the maximum possible luminous efficacy) seen as 3.415 Lumen. Even though that 5mw laser is producing 5 times the light intensity of the 20 MCP light, the 5mw laser beam will not be visible from as far away as the 20 MCP light with 10,000 lumen. Also, the 20 MCP 10,000 lumen light will reflect a visible spot out to a much greater distance.

This "beam power" affect is the combined affects of beam intensity and amount of lumen within the beam. There is no term for this affect, and so for my own use I just call it "beam power" comprising a unit of "Lux Lumen". I've included this value in the beam calculator for making improvements to the optic design based upon this value rather than solely upon candlepower.

Now we're half way there. Let's make another comparison to realize the other half. Let's now say we have that same 20 MCP 10,000 Lumen light coming from a long focal length reflector in which the vast majority of the light within the beam is uniformly concentrated at 20 MCP. The uniform concentration within the beam coming from the long focal length reflector is due to the distance from the light source to reflector surface being nearly equal from every angle emanating from the source to the reflector surface.

Let's now compare that light to another 10,000 lumen light but having even more candlepower, say 25 MCP. But what if that light is coming from a short focal length reflector? Well, the distance from the light source to reflector surface would greatly graduate over the angles emanating from the source to the reflector surface, with very short distances closer to the rear of the reflector, and very long distances closer to the front of the reflector. This highly graduated distance from source to reflector produces a beam of highly graduated intensity, from a highly concentrated small spot fanning out to a large dim flood. This is because the very large "source to reflector distances" of the small portion of light toward the front of the reflector produce a small amount of highly collimated light, and the very short "source to reflector distances" of the rest of light behind the front of the reflector produces a large amount of barely collimated light.

So how does this affect how we see the beam in the air and how we see the reflected light at a distance? The combined affects of intensity and lumen directly determine this affect. Because only a small portion of the 10,000 lumen of the short FL light is actually concentrated at 25 MCP, and because the vast majority of the 10,000 lumen of the long FL light is concentrated at 20 MCP, the lessor candlepower light would actually produce a more visible beam in the air, as well as a more visible spot at distance.

Since the combined affects of intensity and lumen directly determine the visibility of the beam and reflected light at distance, neither just a lot of lumen alone nor just a lot of candlepower alone will produce a highly visible beam from a distance. The combined affect of this beam power is determined by simply by multiplying the lumen within the beam by the intensity of that lumen. But that only works if all of the lumen within the beam is uniformly concentrated. A graduated beam would need to be sliced into circular portions from the center out, the amount of lumen within each portion is multiplied by the Lux of that portion. The multiplied values of all the portions are summed to a total beam power value. The more portions, the more accurate the calculation.

Below are two beams generated with the beam calculator. The light sources and reflectors vary among them to produce the two different beams that exactly match our examples. One beam from a short FL reflector having 25 MCP and 10,000 lumen in the beam, and the other having just 20 MCP with also 10,000 lumen in the beam while having actually 26.27% more beam power. You can see how the graduations of the beam profiles differ. I also use LuxLumen as the unit for beam power, as it's simply the sum of the beam's graduated portions' Lux times lumen.

Since the "Lux Lumen" varies according to the distance at which the intensity is measured, Lux Lumen is relative to distance. A stand-alone unit of beam power would be evaluated as the "Candlepower Lumen". I'll probably incorporate that into the beam calculator as well, but since the calculations for the two beams below were taken at 3280 ft, nearly 1 km, the "Lux Lumen" in this case is equivalent to "Candlepower Lumen". Edit: I actually should have calculated at 3280.839895 feet (1 km) for this to be fully equivalent, and the calculated "Lux" and "Candlepower" would match exactly as well as the "Lux Lumen" and "Candlepower Lumen".

Please note that the highlighted portions generated by the beam calculator are not the portions used for calculation, they are simply highlight 5 incremental portions to make it easy to see and compare the intensity profile of the beam. The beam calculator actually uses 180 increments to calculate beam power. Also, please excuse me when I should be using the term gradated in replace of graduated, it's just habit.

(The following beam profile is NOT the Nightsword, it's an example application of beam power)






Even though the center of the 2nd beam appears brighter, it's not. This is due to the beam power affect in which there is more amount of high intensity lumen in the 2nd beam. Among these two images, the 2nd beam's intensity is actually generated relative to the slightly more intense beam center of the 1st beam to compare as if they were both on at the same time.

Edit... I think a better name for this would be net illuminance because it's actually the aggregate sum of each lumen's illuminace within the beam.

[Davekan]

This is very interesting, even though the light gather is much worse in the second case. The beam is much better in the lower cp longer fl version.

Dave

[get-lit]

Dave, we're not comparing lights with the same light source. Two different sources and reflectors were used to make the comparison to show that, irrelevant of how the beam is generated, be it a searchlight or even a laser, the power of the beam we see is actually due to the "net illuminance" of each lumen within the beam rather than peak illuminance or candlepower. I've added to the post that a better name for this phenomenon would be "net illuminance".

If the same sources were used, the total beam power or "net illuminance" would be exactly the same for lights of the same aperture diameter, with minimal variations based primarily upon how each optimizes the illuminance profile and shape of the light source, and minimizes losses due to the the vertex hole diameter. Here's a comparison of two beams from the same source and aperture diameter, the beam power or net illuminance is the same...

(The following beam profile is NOT the Nightsword, it's an example application of beam power)

[BVH]

Get lit you have a great way of making a difficult technical subject much easier for us non-experts to understand. I read slow and repeated certain lines but I have a pretty good grasp of what your saying. And I can easily and emphatically say, now that I've seen the ACR600 and Maxabeams side-by-side beams and spots on a target, that I highly prefer the light product from a long focal length reflector. I guess it more resembles a laser beam which I have always found very impressive. Thank you for taking the time, as you frequently do, to create your technical posts!

[Davekan]

Thanks for the clarification. I have to agree with BVH on this. A sharp cut off does look way better.

Dave

[get-lit]

Ok guys, I need some more feedback. I can make a minor tweak in the design to optimize for one of the following...



Edit.. Spacing the below image from that of above to describe that the image below and left is the beam profile for the light on the left above optimized for beam power or net illuminance,
and the image below right is the beam profile for the the light on the right above optimized for max lumen output.


Which do you prefer?

[BVH]

I need to go back and re-re-read your info. Done!

Will the "Optimize Net Lumen" (ONL) option provide more beam visibility and more target visibility? Is the "ONL" option using a longer focal length reflector and does it produce a beam which is more uniformly concentrated. ?


New ?. In the lower model pic in post 221, would the spot be about 72' wide at the 3280' range? I based this on 8000 inches = 666 feet and the beam spot is 1" wide and the field of view pic is about 9.25" wide. So 666 / 9.25?

[get-lit]

The beam profiles in posts 219 and 221 are not of the NS. They are simply examples to illustrate the phenomenon of beam power as a combined affect of candlepower and amount of lumen in the beam. Do not use those profiles for estimations regarding NS.

However, in my last post #224, the NS light on the left is optimized for "net illuminance" or overall beam intensity, beam power, or whatever we want to use to identify what it is that makes the beam and light on target more visible. It has a slightly longer FL than the NS on the right, and the beam has 6% more "net illuminance" so it will be 6% more intense "overall" but with 8.9% less lumen in the beam.

The best way to visualize the affect this has on the beam is to look at the two side-by-side beam profiles in the 2nd image in that last post. It's a subtle difference, the one on the left is just a tad brighter, but with a tad less light in the beam, while overall being also a tad more powerful overall. Just compare the two beam profiles and decide which you prefer.

[BVH]

The beam profiles in posts 219 and 221 are not of the NS. They are simply examples to illustrate the phenomenon of beam power as a combined affect of candlepower and amount of lumen in the beam. Do not use those profiles for estimations regarding NS.

Yes, I understood this. I was just trying to see if my calculation that the beam spot from the fictitious light source in that model would be approximately 72 feet in diameter at a distance of 3,280'?

However, in my last post #224, the NS light on the left is optimized for "net illuminance" or overall beam intensity, beam power, or whatever we want to use to identify what it is that makes the beam and light on target more visible. It has a slightly longer FL than the NS on the right, and the beam has 6% more "net illuminance" so it will be 6% more intense "overall" but with 8.9% less lumen in the beam.

The best way to visualize the affect this has on the beam is to look at the two side-by-side beam profiles in the 2nd image in that last post. It's a subtle difference, the one on the left is just a tad brighter, but with a tad less light in the beam, while overall being also a tad more powerful overall. Just compare the two beam profiles and decide which you prefer.

Somehow, I got it backwards despite having read the info a few times. Makes me wonder how I did that. I did think that my eyes detected the left spot as being just a bit brighter. I am after "what makes the beam and light on target more visible" so Optimized Net Illuminance is my preference.

Can you post the Optimized Net Illuminance model of the actual NightSword as spec'd now? I'd like to see the data and how large the spot would be at the 3280' distance you've been using.

I'm a numbers and data guy so I'm having lots of fun playing with this. This is one of my all-time favorite threads!

[get-lit]

Here you go... I'm now doing calculations at 3280.839895 Ft for 1 Km.

Keep in mind, this is without the retro-reflector. The retro-reflector measures a 35% increase so multiply the results below by 1.35. So you're looking at 63.855 Lux @ 1 Km, 63.855 MCP, and 37613.392875 Lumen in the beam, and 27619.72884 Net Illuminance...



Something significant to note is that we could increase the focal length to gain even more CP at the expense of increased lumen loss within the beam, and "up to a point" net illuminance (beam power) will continue to increase, until the point at which the hit from the lumen loss overtakes the gains from the CP as the source is moved further from the reflector of the same aperture diameter, at which point, the net illuminance (beam power) will then begin to decrease with further FL lengths.

I explored this with the calculator and found that, with this design with same aperture diameter, the optimal focal length strictly for net illuminance (beam power) is 7", which would produce another 85% in net illuminance (beam power), with 159 MCP and just 37613 Lumen in the beam. Beyond that focal length, the loss in lumen overtakes the benefit in CP and the net illuminance (beam power) decreases back down. But going with a longer FL than the 3" here makes the entire reflector housing become bulky and very much forward heavy because the entire diameter of the aperture has to move forward any distance which the FL is lengthened.

This brings me to another very important point I've been wanting to make, regarding the decision a few years back to go with this configuration over the specialized XBO 500 W/RC OFR with super short arc and 260,000 cd/cm^2 average luminance and only 0.8x0.7mm arc gap. It would have produced 138 MCP with this optic design, which is more than double the current ~64 MCP. Some members were disappointed in my decision, but what I realized then but did not know how to quantify nor articulate at the time was this affect of net illuminance (beam power) in relation to both CP and lumen in the beam. This current configuration, although with less than half the CP of that previous plan, produces 2.59 times the net illuminance (beam power) due to 5.8 times the amount of light in the beam.



Edit... Some longer FL considerations over the current 3" FL:

3.5" FL
Moves exhaust vent forward by .5"
Moves entire aperture forward by 3/8"
17.6% Less Lumen in the beam
14.1% More CP
9.6% More Net Illuminance (Beam Power)

4" FL
Moves exhaust vent forward by 1"
Moves entire aperture forward by 3/4"
30.6% Less Lumen in the beam
29.9% More CP
20.8% More Net Illuminance (Beam Power)

4.5" FL
Moves exhaust vent forward by 1.5"
Moves entire aperture forward by 1"
42.5% Less Lumen in the beam
43.4% More CP
29.1% More Net Illuminance (Beam Power)

5" FL
Moves exhaust vent forward by 2"
Moves entire aperture forward by 1.5"
50.9% Less Lumen in the beam
51.3% More CP
38.5% More Net Illuminance (Beam Power)

I'm not sure I'd want to be sacrificing any more lumen output and making the reflector housing any larger.

[BVH]

Do you have enough published data on the NightSun light and lamp to run a comparison model? A NightSun held in one hand would be unbelievable if I didn't know of this thread.

[Lips]

Ok guys, I need some more feedback. I can make a minor tweak in the design to optimize for one of the following...



Edit.. Spacing the below image from that of above to describe that the image below and left is the beam profile for the light on the left above optimized for beam power or net illuminance,
and the image below right is the beam profile for the the light on the right above optimized for max lumen output.


Which do you prefer?

I'd say the one on the right, almost identical to the eye in brightness overal but larger... Looks like the light on the right is slightly larger... If I had it in front of me I'd tell you in a second! Which one do you like :-)

Do either options have better focus ability going from spot to flood? It's hard to put in the mind how this thing beam focus will look real-world. Is it going to focus similar to a Maxabeam or some other light to reference to... May help some minds wrap around it better.



----

On another point while looking at the light I was wondering about mounting points so you don't have to hand-hold the light all the time (10 #'s). Have you considered any type of 3 side mounting capability made into the carbon fiber body. Something for a heavy tripod or rail mount system...

[get-lit]

Do you have enough published data on the NightSun light and lamp to run a comparison model? A NightSun held in one hand would be unbelievable if I didn't know of this thread.

Sure do. I've overlaid the Nightsword beam @3" FL w/retro-reflector on the lower right...


Edit... I've been made aware the Nighsun dimensions are slightly different, and after plugging in the new dimensions the beam is about the same visibly. See this post for clarification.

[get-lit]

I'd say the one on the right, almost identical to the eye in brightness overal but larger... Looks like the light on the right is slightly larger... If I had it in front of me I'd tell you in a second! Which one do you like :-)

Do either options have better focus ability going from spot to flood? It's hard to put in the mind how this thing beam focus will look real-world. Is it going to focus similar to a Maxabeam or some other light to reference to... May help some minds wrap around it better.



----

On another point while looking at the light I was wondering about mounting points so you don't have to hand-hold the light all the time (10 #'s). Have you considered any type of 3 side mounting capability made into the carbon fiber body. Something for a heavy tripod or rail mount system...

Thank you for your input regarding which variation to go with. The one on the right is slightly deeper to catch as much of the light from lamp as possible, but being deeper makes it a bit closer to the source, which is why is has slightly less CP. More lumen or more CP is the trade-off I'm considering, and the resulting "net illuminance" value helps me along. The brightness comparison among these probably varies based upon how different monitors may ramp the light levels.

I had considered a 2-point rotating lockable mount like the Thor, but I think you're describing a gimbal style mount. I don't have time to come up with such a gimbal, but I'll include side mounting threads located at the center of gravity for those who'd like to get creative.

As far as de-focus ability, both of the two options posted are of very long FL with just a minor difference (3" vs 2.75") and therefore both have very large holes when de-focused. That's the nature of long FL, it's mostly for throw. I can say that when I defocused the beam in the clouds, there was so much light up there that the reflection of the clouds sort of obscured the hole. Below is the beam fully de-focused. I've overlaid the focused spot in the center for comparison. Also, I had to enlarge the F.O.V. by 4x to capture the full size of the flood in relation to the spot. The flood spreads to about 32 degrees. The SX-16 flood is 20 degrees. (The brightness of the flood in this profile is relative to itself, not to the spot within it)

[BVH]

That's a very graphic comparison - thank you! I see the Nsun is a 10" reflector with a 1.5" FL. Is that FL considered medium, short or still at the edge of Long?

In my mind, I'm using the standard 4 degree minimum NightSun as a frame of reference with which to try to visualize how the Nightsword will look at my range. One of the missing pieces of data is how I've typically seen the "standard performance" NightSun in operation on a typical police chopper - whether it's been in flood, mid-focus or fine, which is 4 degrees. Of course I'll never know. I see the NS EP is 80,000,000 to 100,000,000 CP and I'd guess it gets this increase by going down to 1 degree because it uses the same lamp and the reflector is the same diameter)

Am I ever excited!

[get-lit]

Yes, 1.5" FL is medium, right smack in the middle I'd say. Go in either direction and CP increases because the source becomes distanced from either one end of the reflector or the other, but they couldn't go any longer because the flood hole would become more an an issue for the application, and they couldn't any go shorter because too much light would be wasted though the vertex hole which needed to be large enough for air flow.

Edit: If you want to see something very similar, look at the photos in this post, from when I had planned on making something geared more for versatility as well. It's also a 1.5" FL, but with a smaller vertex hole and 10.5" CA, so that was a bit more powerful than SX-16 but nothing like the caliber we're talking now.

Also for comparison, the light in this photo had less than half the CP and beam power as this as well.

[get-lit]

These are the options I'm considering. I'm included a beam profile of the SX-16 for reference, kinda shows I'm splitting hairs relative to that. When I look at the rendered beams, I don't see enough difference to justify the added bulk of the 3.5" FL which has less light within its beam while being more powerful overall.

[BVH]

The 3" seems like good middle ground and as you say, it's splitting hairs as compared to the NightSun. Plus, it looks to be the shortest in length.

[langham]

Is their a de-cernable difference? Can you really tell the difference when the light is that powerful? What distances are you talking here? The only way you could tell would be to go off a couple miles, so are you going to make if just for the sake of saying that it has more than 75mCp or make something that may actually be used? It looks impressive regardless of which you go with, I like the 2.75" because the larger spot would be needed at these distances, but I don't think I would be allowed to purchase something like this anyway.

[get-lit]

Thanks langham. You are absolutely correct. I thought I'd be getting a lot of feedback to go longer, and I was hoping not. So there's some reason in this forum LOL.

Going longer on the FL is mostly for bragging rights, not for any practical gain, practicality decreases actually. I would go with 2.75", but there are two things holding me at 3" FL. Firstly, there is an entire range of CP gains to be had by going longer on the FL, all of the way up to 7", which is pulling me in the 3" direction away from 2.75". I'm also more comfortable with 3", as it's more of a standard, whereas 2.75" is entirely proprietary. The lumen loss between 3" and 2.75" is marginal enough for me to opt for 3" for these two reasons.

Edit: Also, the 3" FL actually has more lumen output in flood than the 2.75", more than the 4" as well. That does it, 3" FL it is.

[get-lit]

I was just made aware that the Nightsun reflector is just under 10" CA, and with a 1.3" FL rather than 1.5", and with a 3" vertex hole rather than 2.5". So it is tipping a bit toward the short end of FL at the expense of Lumen loss, it's light gather is under 50%. CP is actually a few MCP higher than I had previously calculated due to the added length between the source and the front of the reflector, but total beam power is a bit less due to the additional lumen loss with the shorter FL placing the lamp closer to the larger vertex hole.

The bigger issue for the Nightsun with these dimensions is that as the source is moved rear of the FL for flood, even more light is lost through the vertex hole. Full flood is only at 20 degrees and light gather is only 44% at that point. The Nightsword will reach 32 degrees still with 89% light gather. If the Nightsun were to flood 32 degrees, it's light gather would drop to 39%.

Edit - For anyone who's seen a Nightsun flood, here's how the Nightsword would compare at the Nightsun's max 20 degree flood (much brighter but with much bigger hole)...

[shuen]

get-lit,
Your calculation is based on point source or actual source shape & size?
Which one withstand more tolerance/various?

Wilson