What's wrong with my surefire(s)?

flashlightpoor · Dec 19, 2006

I have a surefire M3, A2, and U2. My M3 produces less light with the MN11 lamp than the U2. The M3 should produce 225 lumens to the U2s 100. Can bulbs deteriorate but not burnout? Also the M3 last 13 minutes (20 is claimed) with the MN11 lamp and gets so hot it is impossible to hold (measured 144 degrees F. I know these lights will get hot, but this seems excessive. Similarly, the A2 gets so hot I was using it once to change a tire, had it perched on the sidewalk to illuminate the wheel, and after about 15 minutes I went to pick it up and was surprised by the heat, I dropped it down a sewer drain. If it wasn't for the lanyard I would have lost it. The U2 seems to be the best SF light I have seen. It is not only bright but has a very uniform, circular,white beam. The M3 has a egg shaped yellowish beam. Is there something wrong with my lights or does every one use oven mitts when handling SF lights?

Size15's · Dec 19, 2006

It's a different kind of light altogether...

Are both the MN10 and MN11 bulbs looking nice a clear like this?

What sort of things are you shining the lights at? Have you compared to two outdoors?

What batteries are you using?

As for the heat - constant-on will mean it gets hot. Were you holding it the whole time it was constant-on?
The High Output Lamp Assemblies are not really intended to be used constant-on - SureFires are mostly intended to be used in short bursts and flashes

flashlightpoor · Dec 19, 2006

Size15's said:
It's a different kind of light altogether...

Are both the MN10 and MN11 bulbs looking nice a clear like this?

yes they do look like that.

What sort of things are you shining the lights at? Have you compared to two outdoors?

Not outdoors. But I have compared them in darkness, and differing amounts of ambient light. I am mostly shining them at white walls. I put an ocean optics spectrometer on them to see if one was just putting out a lot more green light (which our eyes are more sensitive to). the led had several peaks whereas the incandescent was more even. no obvious conclusion from that.

What batteries are you using?

I used surefires and rayovacs.

As for the heat - constant-on will mean it gets hot. Were you holding it the whole time it was constant-on?
The High Output Lamp Assemblies are not really intended to be used constant-on - SureFires are mostly intended to be used in short bursts and flashes

I was no holding them the whole time. but I couldn't handle the M3 after 5-6 min. I wasn't surprised they got h`ot, Hot Surface is silkscreened right on the lights! And I know it is a problem when you want to make a weather tight case and have good cooling, but this seemed excessive. At least there should be something insulating the handle so you can hold on to it? What if you need to search for something for more than a few minutes?

bwaites · Dec 19, 2006

The problem comes in not holding the lights, then picking them up. Your hand is a wonderful heat sink, with your blood system working like a highly efficient cooling system.

Air, however, does not take heat so easily, and when the light sits in open air, the heat is not transferred as readily as in your hand.

I have carried an A2 for miles with it on, the same with an M3, but I have also noted the heat the lights produce when sitting still. ALL very high output lights, and Surefires certainly qualify due to their size to output ratios, create lots of heat.

The LOLA in the M3 actually might be close to your U2, but the HOLA should certainly put out quite a bit more light, unless you somehow were lucky enough to get one of the fabled "X" binned U2's, which put out somewhat upwards of 150 lumens, maybe even as much as 200.

Bill

flashlightpoor · Dec 19, 2006

More than your hand or air Aluminum is a great conductor. So heat from the head flows to the whole body. If there were a delrin spacer or something between the head and the body, the body wouldn't get to be over 140 degrees.
My U2 is insanely bright. I don't know anything about the fabled X bin U2s, but it is insanely bright. I am a physicist and I have equipment at my lab to measure total radiated power, so I am going to make those measurements. but still I thoguht something twice as bright as something else should be noticeble. The U2 is definitely as bright or even brighter than the M3.

In the end I think the 13 minutes of battery life is the biggest problem for me. I volunteered for Search and Rescue for four years and everyone on this forum would be surprised by the lights those guys carry-- they are not $300 SFs. And they need powerful searchlights, but something with 13 minutes of battery life is little more than a toy for that kind of work.

benchmade_boy · Dec 19, 2006

flashlightpoor In the end I think the 13 minutes of battery life is the biggest problem for me. I volunteered for Search and Rescue for four years and everyone on this forum would be surprised by the lights those guys carry-- they are not $300 SFs. And they need powerful searchlights said:
so what kind of lights do S&R use? and wouldnt a m3t be a good light?

flashlightpoor · Dec 19, 2006

benchmade_boy said:
so what kind of lights do S&R use? and wouldnt a m3t be a good light?

When I was doing it we carried 4 AA princeton tec halogen lights for personal, and large rechargeable searchlights that looked like dive lights. I don't know what tech those lights used, maybe HID? The princeton's where plastic bodied totally waterproof and lasted 4 hours, had a included acessory cord lanyard, and were very oval shaped--they didn't roll if you put them down. Also they cost $20. They were comfortable to hold in the cold, because plastic is a poor conductor, and easy to twist the large head on/off with mittens. Whereas twisting the small SF cap isn't as easy in mittens.

These days I am told they carry HID searchlights and LED personal lights made by Inova. But they are experimenting with handheld HID lights-- the current hesitation being the battery life is only about 1.5 hours.

Size15's · Dec 19, 2006

Take your flashlights outdoors and you'll really see the difference.
If your white walls are only a couple of metres away the M3 isn't getting a chance to stretch its legs compared to the U2 that is more at home at closer ranges.

Also, give the MN11 another try - hold and use it this time whilst doing a constant-on runtime "test" if you like.

The MN11 isn't for search and rescue - In fact most SureFires have runtimes intended for activites such as so-called "tactical" encounters that last minutes at a time.

Jumpmaster · Dec 19, 2006

flashlightpoor said:
I volunteered for Search and Rescue for four years and everyone on this forum would be surprised by the lights those guys carry-- they are not $300 SFs. And they need powerful searchlights, but something with 13 minutes of battery life is little more than a toy for that kind of work.

Different application. If you find that you are not the target market for Surefire lights, you are probably correct. They are "tactical" lights and I was fortunate enough to personally hear PK's explanation of what that means. They are not meant for SAR use. You would have had to hear PK's take on what "tactical" is for it to make sense (and I will not pretend I can convey it as clearly as he did), but short runtimes are fine in LEO and MOUT situations...at least the ones SF's are intended to be used for (room clearing, etc.)

I have no problem whatsoever with the heat and runtime of my M2 and M3...

JM-99

What's wrong with my surefire(s)?

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