New Here...

Hi all, I was welcomed by Ra in another post. When I was interested in BIG portable lights nine years ago, nobody else had any interest, it was just me and I thought I was crazy then. Now I'm looking at the posts I've missed over the years and I'm completely amazed at what I see. Lots of experimentation and ingenuity, but still don't see much that beats the Xenon short arc lamps for putting the most light a few miles from a portable light. I read up on the Ushio Emarc but see that even with its tiny electrode gap the luminous area is much larger than the Xenon's. Even Spectrolab continues using this lamp in heli searchlights with the new Nightsun II.

I see Ra's amazing Maxablaster uses a Mercury short arc lamp throwing light past 4 miles. Can anyone get me up to par on other methods that have been proven? I'm a bit more interested in getting more light out to only a few visible miles. Right now I'm hung up on the Xenon XBO 500W/H OFR and I'd prefer to stick within the 500W range for portability. Any knowledge as to whether the HBO 500W could outperform the XBO 500W in front of a 9" or smaller high grade reflector?

500W :eeksign: most people around here are keeping HID lamps under 150Watts only thing that powerful (not output wise anyways) are the halogen guys. Ra has made a very nice light shoots like over 6100meters I believe.

Get-Lit, welcome to CPF's! I know for a fact that my XeRay 75W "BarnBurner," and the Larry14K (see thread on aircraft landing lights) lights a lighthouse in Long Island Sound which I have done from between 1.9-2.1 miles on shore...on a clear, low humidity, low moon night.

Obviously, neither compares to Ra's MaxaBlaster, or the MaxaBeam lights in terms of throw...but both are much more affordable.

LuxLuthor said:

Obviously, neither compares to Ra's MaxaBlaster, or the MaxaBeam lights in terms of throw...but both are much more affordable.

Click to expand...

The LK14 can't throw as far as the Maxablaster or Maxabeam?

I don't bealieve that... the Maxablaster is only 4000 lumens as said by Ra.

Ad if you look here the LK14 looks like its owning the Maxabeam

http://homepage.mac.com/rouses/beams/PhotoAlbum349.html

Larry is losing a lot of light through his reflector.

That's lots a light in that photo comparison! Although the MB just might light that tree beyond the distance in which all those less collimated LK14 lumens can't reach effectively. Hence my interest in the 500W Xenon.

Well I guess I can understand why the LK14 can't ouththrow the maxablater, but a Maxabeam? I'm a bit surprised.

It has to do with light point source size, lumens output of the lamp and the beam collecting and shaping abilities of the reflector. The Maxabeam has a very small light point source and a darn good reflector. Think of the Maxabeam as a laser. Not too many lumens but a heck of a throw.

Exactly, consider a laser at a mere 1W with very few lumens would far outperform anything any feasible light could as far as candlepower.

Hi Get-Lit,

You probably already know this, but if you want maximum throw (technically candela or candlepower) then the only thing that matters is surface brightness (technically called luminance). Lumens and arc size are irrelevant (although arc size and surface brightness are closely related, for a given number of lumens smaller arc sizes will have higher surface brightnesses). So when looking at the specs for lamps you should focus on finding one with the highest possible surface brightness. Surface brightness / luminance is usually measured in cd/cm^2.

When it comes to high surface brightness the classic choice is xenon short-arc as you already know. However it is very old tech and suffers from very low efficiency (around 30lm/W in the 500W range, 40lm/W in the multi-kilowatt range) and short life, but it is also the only HID technology which doesn't take any time to warm up and it also produces the best quality light which is probably why it is still so popular today. The Osram XBO lamps have surface brightnesses ranging from around 40 000 cd/cm^2 in the 500W range to around 100 000cd/cm^2 in the multi-kilowatt range.

As you already know another HID technology with high surface brightness is mercury short-arc which is used in the Maxablaster. The Osram HBO lamps are really designed to produce intense UV radiation, not visible light and don't even have a particularly high surface brightness. Most aren't any better than the XBO line of lamps and in many cases are actually worse. The HBO 500 W/2 has a surface brightness of only 30 000cd/cm^2 vs. 40 000cd/cm^2 with the XBO 500 W/H OFR.

The one exception to this is the HBO 103/W2 lamp used in the Maxablaster. It has a much shorter arc and a much higher surface brightness than the rest of Osram's HBO lamps. It has a surface brightness of 170 000cd/cm^2! This is what allows the Maxablaster to exceed the Spectrolab Nightsun in throw with a much smaller reflector.

Getting back to xenon short-arc lamps, Osram makes a lamp which is much more suitable than the XBO 500 W/H OFR. The XBO 500W/RC OFR is a new (I think) xenon "ultra" short-arc lamp with a much smaller arc and much higher surface brightness than the XBO 500 W/H OFR. Its surface brightness is an incredible 260 000cd/cm^2, 6.5 times that of the XBO 500 W/H OFR! This is even higher that the HBO 103/W2 used in the Maxablaster. The luminance spec is only the average surface brightness, so the peak surface brightness will be even higher still! It's possible that the peak surface brightness is more than double that of the HBO 103 W/2, which means that in the Maxablaster it could produce over 100 million candlepower!

Back again to different HID technologies. Xenon short-arc's main markets are cinema projection and searchlights which need high surface brightness but don't need particularly high efficiency or long life. Over the last 15 years or so a new market has emerged which needs a lamp with high surface brightness, high efficiency and long life: portable (compact) consumer projectors. They need high efficiency because of their small physical size which is unable to dissipate much heat, they need long life because they are a consumer product and they need high surface brightness because of the small size of their optics. In fact because of their small optical system they need a light source with a surface brightness even higher than that needed by cinema projectors! So a new light technology with higher surface brightness, higher efficiency and longer life than xenon short-arc was needed.

The first such technology is short-arc metal-halide. It's around 60 - 70lm/W, or twice that of xenon short-arc and the HBO 103 W/2 used in the Maxablaster. Surface brightness can come close to or even exceed that of xenon short-arc. The Ushio EmArc you mentioned above is an example of short-arc metal-halide. Osram also make a short-arc metal-halide lamp for projection called the VIP R 273/45. It has a surface brightness of 100 000cd/cm^2 and an efficiency of 63lm/W. However the life of short-arc metal-halide is still rather poor and the surface brightness still isn't high enough, so an even better technology was developed by Philips: Ultra High Pressure Mercury (UHP).

UHP lamps have roughly the same efficiency as short-arc metal halide lamps, but have an even higher surface brightness and longer life. 200 000cd/cm^2 seems typical. UHP lamps are mercury discharge lamps, similar to Osram HBO mercury short-arc lamps, but are still very different and have significantly better performance characteristics than the Osram HBO lamps. I don't know the technical reasons for this, but it's probably due to the pressure. As the name suggests UHP lamps are ultra-high pressure, probably significantly higher than the Osram HBO lamps. The HBO 103 W/2 used in the Maxablaster has performance characteristics much closer to UHP lamps than the rest of the HBO product line, it probably has a higher pressure than the rest of the line and may be designed for projector use. However despite having a similar surface brightness to UHP lamps it is still less than half as efficient and has a much shorter life. Osram actually make their own UHP equivalent lamp called the P-VIP which has a surface brightness over 200 000cd/cm^2 although they have only ever briefly mentioned it in their literature, I can't find a datasheet anywhere on their site.

There is an excellent article on UHP technology here: http://www.iop.org/EJ/abstract/0022-3727/38/17/R01/. One interesting technology is a dichroic reflector coating on the inside of one hemisphere of the arc capsule to reflect light back into the arc allowing much smaller reflectors to be used. They say it increases output by 20 - 30%. It also mentions an experimental UHP lamp with a 0.3mm arc-gap and an even more incredible surface brightness of over 600 000cd/cm^2. In the Maxablaster this would produce over 150 million candlepower, more than the AN/VSS-1 searchlight on overdrive! Combined with the dichroic coating and a higher reflectivity reflector (such as silver) over 200 million candlepower should be possible from the Maxablaster! This is my dream light, although I doubt anyone would be able to obtain this experimental lamp from Philips (someone prove me wrong please!) As far as I know UHP lamps are pretty much standard on projectors these days, although some lower end and older projectors still use short-arc metal-halide.

One final technology is xenon "ultra" short-arc which isn't really a new technology, just standard xenon with a much shorter arc. These can meet and even exceed the surface brightness of UHP lamps (except the experimental UHP lamp mentioned above), but they still suffer from the normal problems associated with xenon: low efficiency and short life. In fact due to the smaller arcs life and efficiency is even less than with conventional xenon short-arc lamps. The advantage of these lamps over UHP is that they are instant on, have better light quality (better picture quality) and are more environmentally friendly (no mercury). The target market for these lamps appears to be high end rear projection televisions and larger high end home theater projectors where the low efficiency isn't as much as a concern due to their larger size.

The Osram XBO 500W/RC OFR I mentioned earlier is an example of such a lamp, although the best example is the PerkinElmer "Cermax" line of lamps. The interesting thing about these lamps is that the arc remains the same length from 125 - 800W so while at 125W they are nothing special by 800W their surface brightness is very high. However they have an integral elliptical reflector which means they aren't very suitable for mega-spotlights (although the $6900 Megaray uses the 175W capsule quite successfully). PerkinElmer also make a 5kW "Sapphire" ultra short-arc xenon lamp for large format cinema projectors, although I've only seen it mentioned in an old press release.

I've ended up rambling on a bit (more like a lot), but to answer your question: for absolute maximum throw the best commercially available lamp in the 500W power range is the Osram XBO 500W/RC OFR. However since you "only" want to throw a few miles you may be better off using a more efficient short-arc metal-halide lamp such as the Ushio EmArc, or a UHP lamp. A 250W UHP lamp produces more lumens than both the XBO 500W/RC OFR and the XBO 500 W/H OFR while obviously drawing a lot less power and easily out-throwing the XBO 500 W/H OFR. Alternatively if you wanted a LOT of light you could use the 600W Ushio EmArc which should still have "sufficient" throw in a large 9 inch reflector to reach a few miles, but will produce more than 3 times the lumens of the XBO 500 W/H OFR while only drawing slightly more power.

In a word - AWESOME! I couldn't have asked for a better summary. I have lots of considerations to make about what compromises are best. This will without a doubt get REAL interesting. Thanks so much.

I only want to add some little details to That_guy's story..

If your goal is to make a portable light, things like forced cooling and alowed burn position of the lamps may become problems..

Particularly higher wattage bulbs have limited burning positions, like horizontal +- 15 degrees or vertical +-15 degrees. This doesn't mean they imidiately explode when operated outside these limitations, but stress on the bulb will be higher and life will be shortened.

Higher wattage bulbs, efficient as some may be, at 500 or 600 watts, they still produce a significant amount of heat, these bulbs need to be cooled with forced cooling!!

Indeed there are better solutions in therms of surface brightness, tho not much better.. The HBO 103/W2 is the best compromise: Burnposition 90 degrees (vertical to horizontal), doesn't need forced cooling, almost highest surface brightness aviable. And 300 hours bulblife doesn't seem much, but for a torch its very much: Its not completely comparable, but remember how long the 5 hour krypton-bulbs in a maglite seems to live..

A rough estimate about the amount of hours I use Maxablaster in one year is about 25 hours tops!! In my case that means 12 years bulblife !


Regards,

Ra.

Thanks Ra. The Maxablaster has without a doubt proven the HBO 103/W2, that's a given. I'm very well aware that in the end, after much contemplating how to tackle the extremes of the alternative, I may look back and realize that the HBO 103/W2 would have saved much time and headache, but unfortunately being human means we have the burden of the unrelenting quest to seek more even if it mean we have to kick ourselves later.

The XBO 500W/RC OFR is nothing less than a monster. At 260000 cd/cm2 for someone that wants the ultimate in *available* brilliance with only 500W, that's the ticket. The problem I have with it is that while costing around $750 with only 200 horizontal burning hours I would end up staring at it afraid to use it once I've gotten over the initial awe. Something more practical would make for more fun in the end. I would do anything to get my grubs on that darned elusive experimental UHP dream lamp. I could hold out for it to be available but who knows when it will be available or if it ever will be. ...and that article on UHP technology costs $80 to access so I didn't get all the details I was looking forward to. UHP sounds promising; a regenerative chemical cycle keeping the discharge walls free from blackening, leading to lifetimes of over 10,000 hours, and with a typical surface brightness of 200,000 cd/cm^2 it's definitely a viable compromise against the XBO 500W/RC OFR. The surface brightness for the UHP lamps make them more attractive than the Ushio EmArcs, although I don't have direct lamp to lamp comparisons as I can't locate any specifications on the UHP lamps anywhere. Is there a good resource for these lamps anywhere?

Sorry get-lit, I didn't realize you had to pay to view that article. It was free when I first discovered it over a year ago. Heres another link which should hopefully work: http://www.cesky-spolek.com/DLP/d5_17_R01.pdf.

To expand on what Ra said about the practical problems at higher wattages:

- Runtime. At 100W Ra's Maxablaster lasts for over one hour. At 500W you'll be lucky to get 10 minutes, 15 maybe with high quality li-po batteries. Although to be honest given the brightness this doesn't bother me too much! And since it's xenon it can be turned on and off as much as you like.

- The ballast. The 100W ballast and inverter used in the Maxablaster is light and compact. A 500W ballast will be big and heavy and unless you get lucky and find a low voltage DC 500W ballast you'll need a 600W+ inverter as well which will also be rather big and heavy. You'll probably be able to fit both in a Thor host, but then you won't have any room left for batteries!

The HBO 103 W/2 is good, but in the 100W range I still prefer UHP lamps (available in 100 - 300W, with 120W and 250W being the most common) which have similar surface brightness but twice the efficiency (and therefore lumens), although since no one has used one yet how it performs reality is uncertain. I haven't been able to find any spec sheets either, all I know comes from the article I mentioned and a few bits and pieces on the Osram site.

Since I haven't seen any spec sheets I'm not actually sure how good the lower power (120W) UHP lamps are. The 200 000cd/cm^2 figure comes from lamps in the 250W power range. Since the lower wattage lamps have the same or similar arc length than the 250W lamps the 120W UHP lamp may have a significantly lower surface brightness and could actually be worse than the HBO 103 W/2. But since I haven't seen any spec sheets this is all just speculation, I really have no idea.

Even though I've just said that the lower wattage UHP lamps probably aren't any good, one final good thing about UHP lamps is the ballast. Since the trend has been towards smaller and smaller projectors a lot of R&D has been poured into making smaller ballasts. The Philips "microbar" ballast is tiny, less than 1/6th the size of the Ushio UBX76 used in the Maxablaster! The problem is that you will probably need an inverter, but since the Maxablaster needs one to power the Ushio UBX76 anyway this doesn't make much difference.

Another problem will be getting one. I doubt you can ring up Philips and ask for a microbar driver and 120W naked UHP lamp so you'll probably have to rip one out of a projector. Since the ballast is smart and communicates with the projector you'll also need to rig up some electronics to "fool" the ballast into working. The UHP lamp itself is also integrated with the reflector so you'll have to pull it out which would be a fair bit of work, and will make securely and accurately mounting the bulb in the new reflector difficult since there probably isn't any mounting mechanism on the lamp itself.

Overall I'd say that the UHP lamp system is theoretically the best in the 250W range and possibly in the 120W range as well, but in practice will be far more difficult to implement than the current system used in the Maxablaster.

Thank you for the article. For as interesting as UHP is, I don't think the time is right for something like this with UHP. I see there's already further improvement on UHP with CPL and some others that will need to play out. The XBO 500W/RC OFR is looking real nice even with the short life. I can deal with that. As Ra pointed out most people don't even notice the 5 hour maglite bulbs. You can't argue with 260,000 cd/cm plus instant on is a big plus. Plus I found them for $570. It would be purely DC, so no AC/DC conversion and filtering. With 18.5v Li-Po batteries, a decent compact electronic current limiting DC/DC converter would be 99% efficient and produce no heat. A 500W Xenon igniter shouldn't be too large. That would leave plenty of room for batteries in a decent host. Oh yeah, the XBO 500W/RC OFR is actually operated at 420W which is also nice. So for now this is the direction I'm looking into unless something better becomes just as easy to fully conceive. These specs are way more than I was expecting to get out of something like this anyways so I'm happy.

Question for get-lit:

Do you want something you can carry around or would a "semi-mobile" unit such as one of the tank lights be more interesting, as they have long run times, great throw, but maybe not what your describing, but tremendous nonetheless, and are not just for a few minutes of "wow" light. If you have someplace to aim those lights, they will really turn night into day for a long way off. This according to some Viet Nam tank drivers who have posted on CPF.

Just wondering what application you are going for.

-HAK

I can't believe what those tank lights can be had for. The lamps alone are worth more than the what they are going for. So are the reflectors. Getting one of those would make life so much easier but I'm going for something that can be carried.

Anyone know where I can obtain a polar diagram which shows the light distribution pattern for the XBO 500W/RC OFR? I have the diagram for the XBO 500W/H OFR. I'm not referring to the luminance pattern within the arc but the intensity profile outside the arc. Knowing this helps to optimize the reflector and gain much more use of the light than expected.