Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

I am a very safety conscious person. I worked for a public agency with an aggressive safety officer in the office next door. It was drilled into me for 34 years. So this may sound counter to my past experiences. You're never going to want to point the light at anyone so UV emissions should not really matter. And a momentary "hit" at some distance is not going to do any damage. Eye damage will occur before any burn damage. I remember someone foolishly putting their hand in front of (2" away from the window) Larry Black's VSS-3 at a get-together. He did, indeed get a slight burn on his hand. There is no UV spec given for the lamps you're considering? But again, not sure I'd concern myself assuming you're aggressive in safety procedures when using the light.

Thanks again for the good input. I agree about skin damage risk from UV being very low; I am more worried about eye damage from UV, though. Good operational safety - never pointing it at anybody - is certainly my intent. The accidental exposure risk is low simply because the probability of exposure is low, with responsible use. Any accidental exposure would likely be very brief, as well.

What about eye damage from UV? Might that occur faster then one could sense pain from the visible light? (EDIT: Answer = Yes, absolutely this can happen!)

I would like to have a better understanding of the level of UV emitted. For example, is it foolish to illuminate a white wall from 50' for beamshots for 15 minutes, without eye protection? I really don't think so. But, I also don't want to use the 'Do my eyes hurt yet?' method any more than I have to!oo:

I wear polycarbonate safety glasses even when testing the 35W HID in my shop, with indirect viewing. I know those lamps are supposed to be UV filtered, but I also know the factory HID lamps in my car have severely crazed/fogged the INSIDE of the plastic housing's front lenses over 100k miles, so there is still some UV. (Saab 92-x Aero if it matters).

I realize this is a very challenging issue that we are unlikely to answer adequately. But in this particular forum, I think it merits some effort to try to understand. I feel that, if we are going to discuss building lights with a lamps that emits 'dangerous, intense UV radiation', then we should try to devote a respectable amount of effort to discussing safety aspects, too. If others hadn't done the same in their short arc threads, I might have read them without realizing there was a significant UV hazard to worry about. Also bulb explosion. Let me offer a sincere thanks to others who have included such warnings!

<<< In case anybody has read this far and not figured it out, don't build something like this just because I am trying to - I barely know what I am doing!

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I've decided while writing this that I must improve the perimeter light baffle, so there is less rearward light 'splash' from light reflecting off the back surface of the lens in the narrow perimeter air gap. You can see how intense this small portion of reflected light looks even with the 35W HID, in the repeat-picture, below. The baffle is not installed, so the back-reflection is clearly visible.

If 90% of visible light is transmitted through the glass (optimistic), that reflection is still up to 10% beam intensity. With the new MSR lamp: 10% of 'dangerously intense UV' will still be 'too much UV', if I am remembering my higher math correctly.

 

[BVH]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

I have a pair of #3 and a pair of #5 clip-on, flip down official welding glasses I use when in close-quarters taking beam shots against my light colored garage door (actually 3/8" thick limestone tiles are getting hit by the spot) The #3's are recommended right in the Spectrolab NightSun manual but I found that the #5's are more comfortable blocking more of the light. Look at the bottom of the chart in the first link to see that they protect from all the dangerous wavelengths.

ww.who-sells-it.com/cy/elvex-2925/elvex-2008-safety-glass-catalog-14636/page-1-fullsize.html

Next link is just a search on Amazon for welders flip-up glasses. They're cheap at about $15 to your door. Buy both.

ww.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=%233%20flip%20up%20welding%20glasses

I also have some number 10 and 12 arc welders pieces of glass that go into the helmet. I use those to sometimes look at the actual arc. I found that using a #12 and a #3 or #5 in combination is more comfortable than just the #12.

On safety, also try to determine if the lamp you are going to use is ozone-free. Many are, some aren't so you don't want to use them in confined/closed areas. You really should be able to get a UV emissions spec on a commercial lamp. And definitely try to eliminate as much as possible the back-scatter. I haven't had to deal with that issue with my commercial made lights.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Excellent, thanks for the links.

I will look around more for a UV emission spec.

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Edit: Here is the spectrum.

As I mentioned above, this lamp has no outer glass UV filter envelope, thus is emits a lot of UV that needs to be respected. It really does.

There is a lot of UVA (315 nm - 400 nm) and UVB (280 nm - 315 nm), and even some UVC (Ionizing UV, 100 nm - 280 nm). UVC is what makes ozone and rips molecular bonds apart, in general. It is not present in sunlight at earth's surface. The atmosphere absorbs it, making ozone in the process.

There appears to be almost as much area under the curve below 400 nm as there is in the visible part of the spectrum (400 nm - 700 nm) !

This is why I am being wary of the hazard.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

My pair of MSR lamps were waiting for me when I got home about an hour ago.

These were both supposedly new, and the pair was priced for the cost of one retail new lamp. eBay, sale not auction, from a dealer of professional DJ lighting equipment. Imagine my dismay when one of the lamps was apparently a failed lamp. There are a bunch of tiny drops of metal stuck to the inside on one side of the envelope, and the electrode gap is too big.

EDIT: maybe not failed completely, but certainly not new and unused, either. There is a pic below. New lamp pics don't have foggy, metal droplet covered interiors or metal on the electrodes. This supposedly new lamp did.

I didn't even open the other lamp to inspect it; I am pretty disgusted right now. No return policy from seller, but I am offering him the chance to accept a return, anyway. I hope not to have to use the dispute process.

Trying to be optimistic rather than cynical...maybe he is some old guy with bad eyes. But I kind of doubt it. Seems a dealer of gear would know better. Fortunately, I have had very few incidents like this, in a whole lot of purchases.

I was hoping to have this light together to bring with us on a trip to the boonies in a week. Not looking good now - I still don't have a ballast to power it, and still no lamps I can test ballasts with.

I will order an actual new lamp from a more reputable source, after I get my refund.

 

[BVH]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

That's very disappointing! I know how you feel, sort of. My Newport 1000 Watt arrived today damaged. The front left corner of 1/8" or thicker Alum was bent 90 degrees+ into the faceplate. It was advertised as most likely a new and unused unit which it looks to be with unopened manual/power cord bag. In my case, the seller had two of the same and he will be shipping me the 2nd unit tomorrow at no cost. I guess I'm lucky this time. It was packed reasonably well except for the front, only 1.5" of wrapped spray foam.

Sorry about you setback!

 

[BVH]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Sent some PM's on Ebay items

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Quick update: ( I will post more info and pics later when I have time)

I have been busy with this, again.

The seller of the two MSR lamps adjusted the sale price with a partial refund per my counter-offer, so I do own 2 MSR 400 SA lamps. One is sealed, one is used and at least slightly damaged.

I bought a 400W Digital Universal MH/HPS Ballast from a horticultural store for $75.

I hooked the USED MSR 400 lamp up to this ballast to see if it would light. It was in a metal pipe, and I wore welding gear. The lamp struck and lit up dimly right away, then ramped up to a much higher but flickering brightness, and held steady like this for 5 minutes until I shut it down. The arc was wavering around a lot, and seemed a little bit orange/yellow, not intense white like I expected. Upon inspection after shutdown, there were now even more metal blobules in the envelope, and the electrodes seemed to have sustained further damage.

After cooling, I repeated this operation for 10 min. Then for 20 min. Then for 40 min. My thinking was that maybe the lamp didn't get hot enough, and it might improve. It did not improve. Always flickering. Electrode damage progressed each time. I will post close-ups showing this, later.

So, this cheap ballast does not work with a used MSR 400 SA lamp. Perhaps this is because I used a lamp that was damaged. Maybe the new lamp would work. But, I really doubt it, and I have not dared to try it.

The ballast Lightsward suggested above MIGHT work, but I'm not confident of that, yet, and it's a $300-400 gamble to find out.

Since I have not found a source for a proper ballast intended for this wonderfully spec'd MSR SA lamp, I will try a different approach next.

I have now purchased one of the lab grade Oriel Short Arc housing and ignitor sets discussed above. No power supply, yet.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

I got the Oriel equipment for a good price via 'make an offer' so it is not a big risk. It is designed for true Short Arc Xe or HgXe lamps, and not suitable for the MSR lamps. Oriel's starting voltage is something like 40 kV, so I think a double-ended lamp is needed for HV isolation distance. The lamp holders for single-ended lamps like the MSR are typically only rated for 5 kV.

I still want to use the 30k Lumen 400W MSR lamp if I can. MSRs are MUCH easier to mount and keep at their happy temperature, and they can run in any position. They are AC lamps.

The Oriel gear is DC power. The Short Arc lamps I could run with the Oriel equipment would be XBO or HBO type lamps. 200W are the biggest common size for the lamps and power supplies, although the 200W power supplies are technically capable of 300W according to the documentation. HBO 200W lamps put out only 10k Lumens. Smaller arc, sure, but I think that might be overkill with my big reflector; 3x more Lumens from the MSR is my strong preference.

I will keep looking for a proper ballast for the MSR lamp, but I'll probably grab a 200W Oriel power supply next, and a lamp to run with it. 500W 110V Oriel power supplies are available, but awfully expensive - so much so that it would be cheaper to just buy a new, complete 575W MHI lamp Fresnel production light from China. If I could find one cheap that would make for a nice setup, though.

With an Oriel 200W universal supply (Model 68805) is the HBO200 is my best lamp option, I think?

 

[FRITZHID]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

I got the Oriel equipment for a good price via ............... Smaller arc, sure, but I think that might be overkill with my big reflector; ..........

Um.... I'm confused... "overkill"? This is not a phrase I'm familiar with.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

OH, here are pics of the MSR testing. I hope I have kept the pics of each test straight - I took way too many and should have put labels in the pics, but didn't.

These are high res, you can blow them up for a closer look by clicking at the top banner of each as usual. For highest resolution, though, click the image itself to go to Photobucket, hover briefly over the image that loads there, then click the magnifying glass icon.

This is the inverter:


Here is the lamp as received:


Here is the lamp holder in the test rig:


Pipe and screen added for burst protection. No fan cooling; the MSR lamps are passive cooling capable:


Lamp running near end of 10 min test, the 2nd run, I think. This is outdoors on a sunny afternoon, but in the shade:

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Close-ups of lamp envelope and electrodes after various runs are below. Over the course of the testing, the electrodes clearly degraded. The metal droplets move around a lot from test-to-test, too. Some light scratching is visible on the outside of the quartz envelope, too. This in not from me; I only touched it with an alcohol dampened Kimpex wipe, nothing hard.

This lamp looks like is has way too much metal inside for it to simply be the mercury added for lamp operation, right? Photos of new lamps show nothing like this, at all.

This is after a 10 min run. Note there is now a large glob of metal on the lower electrode, and appears to be less on the glass:






This is after a 20 min run. Note the red deposits....mercury can form red salts/pigments, I think. There is also now much less metal on the electrodes, and more on the glass:







Any observations are welcome!

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Here is a photo taken as quickly as I could after shutdown, so I could try to judge if the 2 electrodes were at similar temperature. It is blurry, but shows the upper one is only running a little hotter than the lower one, by my interpretation:


And here's one after another 10 min run. This time the electrodes have a lot less metal condensed on them, but they are showing damage. The amount of metal on the electrodes seems quite small now, and there isn't a lot on the glass, either.

Where the heck did all that liquified-looking metal go?:

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Here are some shots after one more run, about 40 min or so. Electrodes seem to be in bad shape to me. I have put maybe 80-90 min total runtime on it now:

 

[FRITZHID]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

That bulb is def shot. In fact, please be careful using (don't) and handling it at this point.
I have a few 150w hg/xe sa bulbs with this same issue, one burst upon cooldown, another popped in my hand while simply moving it.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Um.... I'm confused... "overkill"? This is not a phrase I'm familiar with.

Yes, I know what you mean.

In this case, I mean that for my goal of a highly visible beam, 3x more Lumens at 1/2 the arc size ( MSR vs "100W" HID baseline) would help a lot more than keeping Lumens at 10k but shrinking the arc size further. (200W HBO vs. "100W' HID baseline).

If I go the route of the Oriel gear and an HBO 200 lamp, I will have similar Lumens to the cheap, easy HID option, but with maybe 1/3 arc length (3x surface brightness???), at 10x the cost!

If I could make the MSR work, I would get 3x the Lumens as either HID or HBO options (30k), and still have about 1/2 the arc size of HID, so maybe 6x surface brightness while tripling Lumens, vs HID! Seems best by far, just not working out for me, yet.

I am not very sure of arc lengths or surface brightnesses stated above; I didn't research this in detail.

 

[BVH]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

As Fritz says, I'd put on very protective equipment and oh so carefully put that lamp in the trash, cover it completely and tightly with something heavy and somehow smash it.

You just don't know what you're going to end up with when running a non-matched lamp and ballast. I'm no AC short arc expert but it looks like the lamp is being very overdriven.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

That bulb is def shot. In fact, please be careful using (don't) and handling it at this point.
I have a few 150w hg/xe sa bulbs with this same issue, one burst upon cooldown, another popped in my hand while simply moving it.

OK, thank you for the caution and for confirming the lamp is shot! The metal halide short arc MSR lamps are not filled to high pressure when cold like the true short arcs. I do wear a full face welding helmet, thick leather gauntlet gloves, and a sweatshirt over a couple of layers when running it. The one exception was for the photo with the metal pipe removed. For that one, I set a 30" section of Sonotube over the lamp, and wore thinner Mechanix gloves. I used only my camera to peek over the edge. So, my hands were briefly exposed to the lamp. But I was very quick - I was worried about burning a spot on the camera's detector more than personal harm, in that event.

Your comment serves to illustrate another very good reason the true SA lamps are NOT my preferred solution. They are a lot more dangerous to handle than the MSR lamps!

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

As Fritz says, I'd put on very protective equipment and oh so carefully put that lamp in the trash, cover it completely and tightly with something heavy and somehow smash it.

You just don't know what you're going to end up with when running a non-matched lamp and ballast. I'm no AC short arc expert but it looks like the lamp is being very overdriven.

OK, instead of running this lamp more, I will do as you suggest. Destroy it safely. I don't think it will burst with much energy, but I should be able to confirm that by the noise it makes.

Overdriven makes sense. Maybe the temperature is too low, so voltage is too low and current is way too high, overheating electrodes. Maybe the ignition HV is staying on, and blasting the electrode away. I thought of trying to measure the operating voltage with my DVM, and decided that would not be smart - I don't want to probe 2 kV if the ignitor is staying on. So, I don't know.

I think it was worth a $75 gamble to try that ballast. If it had worked, I would have found a cheap route to 30k intense Lumens in a great package!

Fail!

Now the question is if I should repeat it with the remaining MSR lamp, and hope for better results. Maybe eventually, if I give up on getting a proper ballast.

 

[JP Labs]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Fritz,

Do you think the lamp was failed, even in the 'as received' picture, or only after I tortured it?

 

[FRITZHID]

Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

Bvh is correct. Cover with some trash cloth (shirt, towel, etc.), 4 layers thick should be plenty, and hammer it, then toss as is.

As far as your main thread post.... it's very basic... Smaller arc = tighter/cleaner beam.... I have a fist full of lights.... from a small reflector 10/30w hid to my hack job 400w mh beast....
Watt for watt... at an honest 83watts for both tests.... true SA xenon beats all others (hid(mh "sa" ), merc/xenon, hbo, xhp......etc) as far as that laser like, super far throwing beam...
Given that the = wattage HID throws a ton more lumens down range, the beam it's huge.