NightSword - Portable Mega Light Idea Revisited

[get-lit]

Ok, the specs for the SMH-850 are pretty impressive. When comparing the SMH-850 to the best XBO 1600.

EDIT: I just realized something in my arc gap comparisons beweeen the XBO 1600 and the Ushio SMH-850. Osram does not list arc gap sizes, but luminance sizes. The actual arc gap sizes are larger. If the two lamps are to be compared, then we have to consider that the smallest gapped XBO 1600 is actually 3.8mm. That then mean that the SMH-850 at 3.5mm has an arc gap advantage, not a disadvantage as I had previously thought. Therefore the following is revised:

SMH-850:
Lumen output: 70,000
Arc Gap: 3.5 mm

XBO 1600:
Lumen output: 70,000
Arc Gap: 3.8 mm

EDIT: Therefore, the SMH-850 has an 8.5% collimation advantage over the XBO 1600. Since the Nightword reflector will have around 26.3% collimation advantage over the NightSun reflector, the total collimation benefit is about 37.14%.

Also, an electronic power supply for this lamp is coming along! Things are really shoring up.

 

[Juggernaut]

I know this is not my light, nor have I contributed to it's constructions both financially and technically, but I have to say it's a shame you rerouted from the most aw inspiring thrower of all time to a super high power spot light. Of course it will still be impressive. It's just that it loses that all important aspect of sci-fi capabilities. Has anyone ever produced a 70,000 lumen portable spotlight? No, but has anyone ever seen what the output / beam of one would look like? Yes. No one has ever packed this much power into such a small size, but on a world wide scale it's output will be nothing special. For $2,000 I could strap 70X 600 watt Par64 bulbs to a piece of plywood and see what 1,050,000 Lumens plus 70x 650,000 Candle Power would look like. Would it be portable, practical, efficient, or usable? No, but it would probably destroy a NightSun in output and throw. However I could strap 1,000 of these bulbs together and never achieve what a 240,000 Average Luminance bulb in a precision reflector could do, nor has any man living today or ever in the past been allowed the privilege of such a sight. 20+ miles of throw would be incomprehensible. Of course this is realizing that this light will still throw many miles, it's just that I would always feel it could be more, that I could have made it something more unique. I just recently finished a hotwired regulated incandescent spotlight which may just be the longest throwing incandescent light on earth, it's 5,000 Lumens of blistering white light can reach out and touch something as far off as 1,500 yards, not much farther then my 1,000 watt GE light. Why on earth would I want a light to throw only a few hounded yards farther then my 27,000+ Lumen aircraft landing light? Well just because! I find the 5,000 lumen thrower 100x more amazing then all 27,000 lumens coming out of the GE light even if it's beam is much more practical. Why?, because it's unique. There is 3 other people in this world that have 1,000 watt GE light, but only I have created such a long thrower as my other light. In the end it really comes down to your decision, on how you want to build this light, and you may not agree with any of my reasoning, but I just wanted to write this just incase you were still on the fence, a lot of my friends always ask if their has been any updates on the legendary space penetrating thrower: "The NightSword", but if you decide not to go for your original design that's fine it's all up to you😱.

 

[get-lit]

I revised the NightSun vs Nightsword comparisons posted earlier because the Osram lists the XBO 1600 luminance area rather than arc size, so to make the comparison more accurate, I had to find the arc size of the XBO 1600 and revise.

Thanks Juggernaut. For what it's worth, the NightSun, with 70,000 lumen, can illuminate 1 lux at 7200 meters. Therefore the Nightsword with the same lumen output and with a 37.14% collimation advantage should illuminate 1 lux at 9874 meters, which is still 6.1 miles. Of cours this is all over simplified. Throw is actually an inverse square relation, but I'm also basing the collimation advantage on simple reflector diameter rather than aperture area or the focal length/light gathering relation. I'm not about to delve into the full formula for etendue so that I can arrive at a definitive comparison, it's the arc size to reflector size concept that's important. In the end, the NightSun has a 4-degree divergence, and the Nighsword should have a 3-degree divergence with the same 70,000 lumen.

In any case, a light of this kind has never been done in any kind of portable light before. To enable something like this to be at all practical is a huge feat. As I intend to make this for everyone, the matter of practicality becomes an issue, and having 5.3 times the light output that can still throw 6 miles is much more practical and impressive for the person behind the light, than compared to 1/5 the light that can throw beyond the distance the person behind the light could ever see. What I have planned is something that can light the #$@% out of anything you can see.

Here's the deal. Over 90% of the work is in creating a ventilated, weather-resistant, portable housing that can host these kinds of powers safely and reliably. Once that has been accomplished, it would take relatively much less effort to create additional replaceable collet mounts for different lamps and to change the ballast. So, once a housing like this has been completed, lamp selection is no longer a mutually-exclusive process. It would then become an issue of obtaining a portable ballast for the other lamp, and the creation of a portable ballast for the other lamp will always still be an option even though we're working on a portable ballast for the SMH-850 at the moment.

The housing is coming along. The design is about finished. I'm thrilled with it way beyond anything I've posted so far, and you will see what I mean. I can't wait to reveal it. It's a long slow process to plan for cost-effective suppliers and fabricators for so many specialized components. The ballast as currently planned will have both DC and AC input from 90v to 240v, so a portable battery pack would have to be at least 90 volts.

By the way, the ballast under way will likely provide for dimming and strobe modes. Strobe mode should be very interesting!

 

[get-lit]

Juggernaut, there is also a discrepancy that's been making me weary of the huge average luminance advantage the XBO 500 W/RC OFR has over the XBO 1600 W/HS OFR.

Please consider the following:

XBO 500 W/RC OFR
Reported Average Luminance: 260,000
Luminous Area: 0.7x0.8mm = 0.56 mm2
Lumen output within that area: 13,000
Actual Calculated Lumen/Luminous Area: 23214

XBO 1600 W/HS OFR
Reported Average Luminance: 70,000
Luminous Area: 1.0x3.2 = 3.2 mm2
Lumen output within that area: 70,000
Actual Calculated Lumen/Luminous Area: 21875

As you can see, there is really hardly any difference at all in the calculated intensities. The XBO 500 W/RC OFR and the XBO 1600 W/HS OFR both equate to squeeze about the same amount of light per unit area. The XBO 1600 W/HS OFR just has 5.3 times the amount of light squeezed into 5.7 times the area. I don't know how they arrived at such a high reported average luminance for the XBO 500 W/RC OFR; it's such a simple calculation that doesn't add up. I think the XBO 1600 W/HS OFR easily has the edge, and the SMH-850 even more so.

 

[get-lit]

Comparing Light Performance:

Here's some useful relations that allow us to accurately compare expected light performance:

Relative Divergence is Focal Length per Luminance Area:

Relative Divergence = Luminance Area/Focal Length

Relative Luminous Intensity is an inverse square relation to Divergence times Lumen Output:

Relative Luminous Intensity = Lumen x Percent Light Gather x 1/(Divergence)^2

Substituting for Divergence:

Relative Luminous Intensity = Lumen x Percent Light Gather x 1/(Luminance Area/Focal Length)^2

Since reflector diameter is essentially the capacity for Light Gather and Focal Length, for reflectors with the same ratios of Light Gather to Focal Length (ideally optimized), we can simplify to:

Relative Luminous Intensity = Lumen x 1/(Luminance Area/Reflector Diameter)^2

Luminous Intensity is an inverse square relation to Throw Distance:

Luminous Intensity = 1/(Relative Throw Distance)^2
Relative Throw Distance = sqrt(Luminous Intensity)



Because the luminance area for the SMH-850 is unkown, arc gaps will be used to compare instead.

NightSun
Lamp: XBO 1600 W/HS OFR
Lumen output: 70,000
Arc Gap: 3.8mm
Reflector Diameter: 9.5"
Known Divergence: 4 degrees
Known Throw: 1 lux at 7200 meters

Nightsword
Lamp: SMH-850
Lumen output: 70,000
Arc Gap: 3.5mm
Reflector Diameter: 12"
Relative Divergence: 4 / ( (12/9.5) x (3.8/3.5) ) = 1.371428571428571 = 2.92 degrees
Relative Luminous Intensity: (70,000 x 1/(4^2))/(70,000 x 1/(2.92^2)) = 1.88
Relative Throw: 1.88 lux at 7200 meters = 1 lux at 9874 meters

So, when going from 4-degree divergence to 2.92-degree divergence of the same amount of light, we get 88% more luminous intensity, and 37% more throw.




Also notice that as there happens to be two countering inverse square relations, luminous intensity to divergence and luminous intensity to throw, luminous intensity can be eliminated from the comparison, and a simple relation can be deduced:

Relative Throw Distance = sqrt(Lumen) x Relative Beam Divergence

And Substituting for Beam Divergence:

Relative Throw Distance = sqrt(Lumen) x sqrt(Percent Light Gather) x Focal Length / Luminance Area

Substituting Reflector Diameter for Percent Light Gather and Focal Length:

Relative Throw Distance = sqrt(Lumen) x Reflector Diameter / Luminance Area

The above makes comparing performances very simple to understand what an optical combination is going to gain you. For instance halving the luminance area will provide for double the throw, as well would doubling the reflector diameter, given that both reflectors have the same Percent Light Gather to Focal Length ratios. i.e. if you double the focal length while using the same reflector profile with the same light gather, the reflector diameter is doubled, as well as throw. Also note that in obtaining the optimal ratio of focal length to light gather for a given reflector diameter, light gather has a direct relation to luminous intensity and a square root relation to throw, while focal length has a squared relation to luminous intensity and a direct relation to throw. Therefore for a given reflector diameter, obtaining the maximal focal length is paramount to throw, at least until the point of diminishing returns in the loss of light gather is reached.

NightSun Relative Throw Distance = 70,000 * 9.5 / 3.8 = 175000
Nighsword Relative Throw Distance = 70,000 * 12 / 3.5 = 240000
Nighsword to NightSun Throw Distance Ratio = 240000/175000 = 1.3714

So if the NightSun throws to 7200 meters, the NightSword should throw to 9874 meters, or 6.1 miles.

 

[BVH]

Way beyond the technical knowledge of light I have but I follow the theory and practical of what you're saying. This is really getting exciting! What an amazing hand-held light source this will be!

 

[get-lit]

Thanks BVH!

I'd like to fully evaluate the average luminance discrepancy between the XBO 500 W/RC OFR and other lamps. Before, I had mistakenly used Lumen per Luminous Area to compare, but the comparison should be Candela per Surface Area, which does give the XBO 500 W/RC OFR a good advantage, but not as much as expected when reading the spec sheet.

With a DC short arc lamp, the Luminous Intensity is emitted from the surface area of an elongated elliptical sphere, and likely around 25% of that area is not utilized due to the electrodes.

XBO 1600 W/HS OFR
Luminous Intensity: 5500 cd
Luminous Area: 1mm x 3.2mm = .1cm x .32cm
Elliptical Sphere Surface Area = 4*3.14*0.05*0.16 = 0.10048 cm^2
75% Emitting Surface Area: 0.07536 cm^2
Average Luminance = 72,983 cd/cm^2 (Right on target)

XBO 500 W/RC OFR
Luminous Intensity: 1800 cd
Luminous Area: .7mm x .8mm = .07cm x .08cm
Elliptical Sphere Surface Area: 4*3.14*0.035*0.04 = 0.017584 cm^2
75% Emitting Surface Area: 0.013185 cm^2
Average Luminance: 136,518 cd/cm^2 (About half of the reported spec)

Average Luminance Difference: 87%

So how does that translate to throw? Well Lux is the inverse square relation of candela to distance:
Lux = cd/m^2

And Average Luminance is the inverse square relation of candela to distance:
Average Luminance = cd/cm^2

They are both on the order of an inverse square relation with distance, therefore, they are both on the order of a direct relation to each other; Average Luminance is a direct relation to throw, and the XBO 500 W/RC OFR with 87% more average luminance will throw 87% further when using the same reflector, and likely around 80% further than the SMH-850. So with the Nightsword, here's our realistic options:

SMH-850
Lumen Output: 70,000
Divergence: 2.92 Degrees
Throw Distance: 1 Lux @ 6.1 Miles

XBO 500 W/RC OFR
Lumen Output: 13,000
Divergence: 0.51 Degrees
Throw Distance: 1 Lux @ 11 Miles

If the XBO W/RC OFR did in fact have an average luminance of 260,000 cd/cm^2, the Nightsword with that lamp would easily through over 20 miles.

So again for the Nightsword, the lamp choices amount to 538% the light output versus 80% more throw.

 

[get-lit]

How lamp manufacturers arrive at their average luminance values doesn't seem to add up for the more specialized lamps. I wonder how they determine their average luminance. The calculated average luminance of the XBO 500 W/RC OFR is about exactly the same as the HBO 103W/2 used in the MaxaBlaster. They are less than 1% difference in average luminance. The new ultra luminance XSTAGE 2000 W lamp by Osram is within 3%, and the higher power XSTAGE lamps are considerably less. With the same reflectors, these will all throw to the same distance, but the higher output lamps will create a wider beam to place more light over a larger area at that same distance.

CORRECTION: The calculated average luminance of the HBO 103W/2 used in the maxablaster actually far exceeds any of the other lamps I've compared, 34% more than the XBO 500 W/RC OFR and the XSTAGE 2000 W. There MUST be something else going on that determines how much of the arc surface area is included in the average luminance figures!

 

[Juggernaut]

Just finished reading your newest, data after replying to your PM, no doubt the SMH-850 will be utterly impressive, while the false claims around the XBO 500 W/RC OFR's average luminance doesn't make it quite as impressive as it once was🙁. I could defiantly see the advantage the SMH-850 has now:thumbsup:. Though I still giggle at the thought of a .54 degree beam throwing 11 miles. I've seen a 2.98 degree beam before it's extremely intense "a lot less floody then I thought. .54 on the other hand is simply incomprehensible:duh2:, I've got a light I built with a .98 degree beam and it throws 650 yards with only 55 lumens! I can't imagine what 13,000 lumens would look like😱!

But anyways now that you have this extremely accurate measuring system "better then anything I could ever come up with!", anyway you could figure out the characteristics of a VIP 120 beam? I know the lamp was eventually scraped from the design faze "what was it? Availability / molded reflector or something:shrug:" but I though it had some crazy average luminance:devil:. I know your not going to build it, but if I ever have enough time and money I still wanted to try that with a 14 inch reflector as I stated long ago😗. You don't have to do the math "I'm no good", but if you want to just humor me, I bet I would get a good laugh:thumbsup:.

 

[get-lit]

Well, it's easy to calculate. If we were to TRUST the manufacturers's provided average luminance specs to all be on a level playing field, the Osram P-VIP 100-120/1.0 P22h DLP Lamp with 200,000 cd/cm^2 average luminance would throw 33% farther than the Maxablaster with the same reflect as the Maxablaster:

200,000/150,000 = 1.3333333

The Maxablaster uses a 33mm focal length, 9.5" diameter reflector. If you were to go with a 14" reflector with the same light gathering to focal length ratio as the Maxablaster, you would gain another 47%:

14/9.5 = 1.473684210526316

Now the Osram P-VIP 100-120/1.0 P22h lamp is an AC lamp, which means it has two peak luminance points, so it would have to be docked at least 25%:

0.75

So multiply all your factors and you got:

1.3333333 * 1.473684210526316 * 0.75 = 1.473684173684211

47% more throw than the Maxablaster. But with all of the discrepancies I've seen with reported average luminance figures, this is definitely not something you can bank on. Also, notice that because the VIP 120 had to be docked 25% due to having two luminance peak regions, it comes out as exactly the same as the MaxaBlaster's HBO 103 lamp, with the only real difference being your larger planned reflector size of 14". Of course the VIP 120 will put out more light however, just not more throw distance.

Until there is a way to know you can trust the manufacturer's reported average luminance values, or if the values can be measured somehow, there is really no way to base a real comparison other than to try it.

Needless to say, I'm a bit discouraged about creating a throw king because of all this, which is just another reason why I'm very happy to instead make a NightSun killer.

 

[get-lit]

Uh Oh!

http://www.policeaviationnews.com/Acrobat/PANewsJune2005.pdf

At this year's Airborne Law Enforcement Association (ALEA) Expo, Universal Searchlights of Omaha, Nebraska is debuting two alternatives to the Spectrolab searchlight. The HeliLight 1™ and HeliLight 2™ are small helicopter searchlights offering 2 – 3 times the light output of the Spectrolab SX-16 Nightsun® allowing helicopters to fly higher, safer and quieter.

HeliLights™ feature commercial lamps, patent pending power supply options, no life limited parts, high speed motors with patent pending slewing, standard mounting, all functions patent pending dual control, FLIR slaving, variable focus, 2 year warranty – all at a price lower than the Nightsun®. Coming soon is the HeliLight 3™, a Spectrolab SX-5 Starburst® replacement. HeliLights use SLASS - the industry standard for slaving a helicopter searchlight to a FLIR. There are over 300 systems in operation and demand still running strong. SLASS is available for FLIR Systems Mark 2, FSI U6000, FSI U7000 and 7500, FSI U8000 and 8500, FLIR Systems Star Safire, FSI Ultra Media, Wescam 12, Wescam 16, Wescam MX-15, Taman POP 200 and Aerial Films Gyrocam. You can find a PDF brochure on-line on the Universal Searchlights website.

http://www.universalsearchlights.com/helilight.html

HeliLight 1 ® - 1450 watt xenon / 1600 watt xenon / 2000 watt xenon, 50/60/80 million candle power

HeliLight 2 ® - 1800 watt HMI, 100 million candle power - Coming Soon!


Also now available is the new Trakkabeam A800 Searchlight:
http://www.trakkacorp.com/tc/searchlight_products.htm#view

 

[Juggernaut]

Uh Oh!

http://www.policeaviationnews.com/Acrobat/PANewsJune2005.pdf

At this year's Airborne Law Enforcement Association (ALEA) Expo, Universal Searchlights of Omaha, Nebraska is debuting two alternatives to the Spectrolab searchlight. The HeliLight 1™ and HeliLight 2™ are small helicopter searchlights offering 2 – 3 times the light output of the Spectrolab SX-16 Nightsun® allowing helicopters to fly higher, safer and quieter.

Oh NO! Competition! We can't have any of that🙄.

Thanks for doing out that math for me:thumbsup:.

 

[get-lit]

Ok, so the Trakkabeam A800 with 21 Lux @ 1km can't touch the Nightword, but those Helilights do look a bit scary. Too bad they took down their PDF specs to really know anything more.

As far as the HeliLight 2, the best HMI type lamp I can find is the Osram HTI 1800 W/SE XS:
HTI 1800 W/SE XS
160,000 Lumen
38,000 cd/cm^2
Arc Gap: 7mm

It's an AC lamp, so it has the disadvantage of two luminance peak regions. The lamp more than doubles the light output of the Nightsword, but at the expense of only about 40% of the throw distance, and more than twice the power consumption of the SMH-850. 160,000 Lumen is a lot of light, but I don't have a clue how they could claim 100 million candlepower with that low of an average luminance, in an AC lamp as well, unless they are measuring close to the aperture and collecting a lot of less coherent light that don't reach far anyhow.

The biggest HeliLight 1 is a 2000 watt Xenon, and unfortunately it appears as though they are not using the new XSTAGE 2000 W lamp because the rest of the options appear to be the standard Xenon short arc lamp wattages. Even the best standard 2000 watt Xenon only offers 14% more throw and light output than the best 1600, and still not enough to throw past the Nightsword with the SMH-850. So unless there is some new lamp tech that I'm not aware of, I don't see any big gains with these new lights over the Nightsword as currently planned.

 

[get-lit]

Thanks for doing out that math for me:thumbsup:.

I just realized, most 14" reflectors are of very long focal lengths like around 3", and at that point if you are not careful, you could be loosing a bit too much light gathering for the focal length gains to not be worth the while. Depending on the lamp's angular luminance distribution profile, you may not be any better off than with a 12" reflector with a 2" focal length.

Remember that when you are comparing reflectors to be sure to use the following formula:

Relative Throw = sqrt(Gather) x Focal Length

So for with a 12" reflector with 2" focal length and 85% Light Gather with a particular lamp:
Relative Throw = sqrt(0.85) x 2 = 1.843908891458577

Now compare to a 14" reflector with 3" focal length 45% Light Gather:
Relative Throw = sqrt(0.45) x 3 = 2.012461179749811

So the 14" reflector would gain you 2/1.84, or 8.7% throw, but at a loss of 47% of the light. Plus the reflector is 2" bigger in diameter. Not really worth it for this example lamp. That's why it's really important to know what's going on with the focal-length to light-gather relation for a particular lamp when comparing reflectors. And that's why I spent so much time calculating angular light output totals from the angular luminance distribution profile for Xenon short arc lamps.

Another note however; deeper reflectors that gather more light also have greater angles of incidence than shallower, longer focal length reflectors. The greater angles of incidence are less efficient at reflectance, and greater angles of incidence have more errant divergence than a perfect 180-degree reflection. So deep reflectors can loose their merit to some degree as well.

EDIT: If you were to go with a 14" reflector, I believe one with a standard 2.35" focal length would be optimal. With 3", you're giving up way too much light gather. A 14" reflector with a 2.35" focal length would give you about 14% more throw with nearly the same light gather than a 12" reflector with a 2" focal length. A 14" reflector with 2.35" focal length would be a very nice reflector indeed.

I ended up choosing a 12" reflector with 2" focal length for the this project because I felt that for roughly 14% less throw than a 14", the 12" is quite a bit more portable.

 

[get-lit]

By the way, I've notived a new advertiser here that is offering what seem to be very nice reflectors, and they have a great selection of the larger reflectors, some over 20" I believe!

I wish there were an advertiser index here so I could find it again. Maybe some day I would make something with a mega reflector and one of those new XSTAGE 7000 W lamps! Although not protable, it would be the most intense beam of light ever. I would still prefer a portable light in the end though.

 

[DM51]

By the way, I've notived a new advertiser here that is offering what seem to be very nice reflectors... I wish there were an advertiser index here so I could find it again.

I think this may be the one you mean: Anyone tried Phoenix reflectors?

 

[Juggernaut]

By the way, I've notived a new advertiser here that is offering what seem to be very nice reflectors, and they have a great selection of the larger reflectors, some over 20" I believe!

I wish there were an advertiser index here so I could find it again. Maybe some day I would make something with a mega reflector and one of those new XSTAGE 7000 W lamps! Although not protable, it would be the most intense beam of light ever. I would still prefer a portable light in the end though.

Don't say stuff like that:devil:, you get all the gears rolling in my head😀😉! I may not be able to do all that surface brightness / average luminance = throw equations. But I do love coming up with battery solutions: Here is a pack idea for that 7,000 Watt light: 33x High Power Polymer Li-Ion flat cells arranged in two packs next to each other would make a pack: 6.82 inches tall x 4.8 inches wide x and only 6.3 inches long. It's weight would be 15 pounds and would have 10Ah of capacity at a bit over 120 volts. Max draw of 100A with max continuous draw of 80A "only need 60A". Run time = 9 minuets 30 seconds. Put this in the back pack with ballast or the ballast on the light. To put it into comparisons I can carry a 40 pound backpack filled with SLAs when using my 1000 watt GE light, so 15 pounds is nothing! The only real problem is price = $2,046 through I think you would agree even if the entire light cost $10,000 how can anyone compete with 650,000 Lumens 5 mile plus throw all portable by one man! I can't be completely sure, but I swear I saw somewhere that BHV's AA spotlight was like 535,000 Lumens, so I'll let you figure out why this would be the most epic thing ever😀!

 

[SemiMan]

Could anyone comment on the accuracy of the reflectors, especially over temperature. While luminosity of the central spot is certainly critical to throw, accuracy of the reflector certainly will be as well. Any comments?

Semiman

 

[get-lit]

Yes that is the ad for the reflectors I briefly checked out.

An XSTAGE light would be the best thrower because of the high average luminance values. Actually, the 2000W and 3000W versions would throw just as far if not a bit further than the 7000W, just with less light. For a portable application, either the 2000W or the 3000W would be all you would need.

The 3000 W has the highest calculated average luminance of the bunch (luminous intensity divided by luminance area surface area), closely followed by the 2000W. Both the 2000W and the 3000W lamps and ballasts would be MUCH more affordable than the 7000W. Overall, I would probably prefer the 2000 W for portability. That's about the limit for being able to use the light in automobiles and boats with "practical" high amp alternators. The 2000 W would throw more than twice as far as the SMH-850 with 14% more light, but with 235% of the power consumption. I don't know how any of the XSTAGE lamps could ever be made portable though, because even the smallest 2000W is 11.8" long and 1.83" in diameter! You'd have to resort to a reflector alignment method, and a zoomable lamp mount would be off the table.

Could anyone comment on the accuracy of the reflectors, especially over temperature. While luminosity of the central spot is certainly critical to throw, accuracy of the reflector certainly will be as well. Any comments?

That is my concern as well. Spec sheets for precision reflectors usually list accuracy ranges. That's helpful to know how close the tolerances are, but I'm not sure how well that reflects how true they are to a perfect parabola.

 

[get-lit]

Ok, I calculated the relative average throw for the XSTAGE lamps and compared them to the SMH-850. The XSTAGE specs say the 3000 W can throw 18% further than the XSTAGE 2000 W, while the calculated relative throws actually show that the XSTAGE 2000 W would throw 10% further than the XSTAGE 3000 W. The XSTAGE 2000 W would also throw 80% further than the SMH-850, so not quite twice the distance.

The XSTAGE 2000 W is an awesome lamp. I'm just not sure if 2.35 times the power consumption would be worth the extra 80% throw over the SMH-850 in a portable application. Not to mention the major lamp size difference, and all the extra bulk and weight of the ballast for that kind of power would be tremendous.

Watt per watt, short arc Xenon ballasts are MUCH larger and heavier than Mercury lamp ballasts for Emarc lamps because short arc Xenon lamps are high current low voltage, while Emarc Mercury lamps are low current high voltage. It's the current that makes the ballasts large and heavy. So while a ballast for an 850W Emarc can be small and just a few lbs, a ballast for a 2000W Xenon would take up nearly 1 cubit foot and would be much too heavy to be portable. Sticking with the Emarc SMH-850. For a practical portable mega search light, it can't get any better.