SUREFIRE torches lumen ratings... are they "doctored" ??

[Fusion_m8]

I was told by a passionate Surefire fan that Surefire torches lumen readings are taken from 100m(328ft) away? ie: 6P's 65 lumen rating(P60 lamp ***'y) was measured from a distance 100m(328ft) away?

Is that the industry standard in which a torch's lumen ratings are measured?

If so, then wouldn't a more focused beam produce a higher lumen rating, compared to a beam with wider spill even though they both are using exactly the same bulb, running the same voltage and drawing the same amount of current?

Comments anybody?
:thanks:

 

[chesterqw]

lumens are measured using an expensive(very!!) equipment called the intergrated sphere

 

[B@rt]

Chester, your post started very offensive, repeating this will result in a ban. :scowl:

 

[LEDcandle]

I was told by a passionate Surefire fan that Surefire torches lumen readings are taken from 100m(328ft) away? ie: 6P's 65 lumen rating(P60 lamp ***'y) was measured from a distance 100m(328ft) away?

Is that the industry standard in which a torch's lumen ratings are measured?

If so, then wouldn't a more focused beam produce a higher lumen rating, compared to a beam with wider spill even though they both are using exactly the same bulb, running the same voltage and drawing the same amount of current?

Comments anybody?
:thanks:

That's lux, not lumens. You are right that a more focus light will produce more lux than a less focused light, everything else being equal.

Lumens is total output of light. So a 100 lumen light doesn't say anything about how far it throws; it might have a diffusing lens in front and absolutely no hotspot while a 30 lumens light (like a Mag 3D) when focused to its tightest can throw pretty far.

 

[Planterz]

Surefire is one of the few flashlight manufacturers that actually are somewhat honest about lumen ratings and runtime. I say "somewhat" because usually runtimes or lumen ratins are actually higher than advertized.

 

[Fusion_m8]

Thats true, I find it somewhat amusing that Surefire would rate the L5 and L6 as both 65 lumen torches with only different runtimes.

Surely an L6 with an extra cell and a larger reflector will punch out more lumens for a longer period?:thinking:

Just check out the beamshots in the dark corridor for the L5 compared to the L6...

https://www.candlepowerforums.com/threads/105935

Its clear from the photos that the L6 is significantly brighter than the L5, but yet both rated as 65 lumen output by Surefire!

Surefire is one of the few flashlight manufacturers that actually are somewhat honest about lumen ratings and runtime. I say "somewhat" because usually runtimes or lumen ratins are actually higher than advertized.

 

[LEDcandle]

a larger reflector will punch out more lumens for a longer period?:thinking:

A larger reflector will increase the lux usually, but does not affect lumen output. As I said earlier, lumens is total output of the light while lux is the 'concentration' of the beam.

 

[js]

The SureFire ratings for lumens are--if anything--conservative and actually UNDER-report the true lumens output. For example, an E2e is rated at 60 lumens, but at the start of run on fresh batteries it is putting out something more like 80 or 85 lumens. Most manufacturers would call this an 80 lumen light.

But anyway, as already mentioned, lumens is intensity integrated over all 4 pi spherical radians, and so says absolutely nothing about intensity or "brightness". There is no distance involved. It is meaningless to talk about "lumens at 100 feet." This is intensity and is a very different measure of the beam.

 

[Fusion_m8]

Gosh, it seems that measuring light output is not as simple as it seems! :lolsign:

Thanks for the explanation guys!

 

[Numbers]

What explanation?
How did the surefire L4 go from 65 Lumens in the SF 2005 catalog to 100 lumens in the 2006 catalog? SF customer service told me it was because they are now better able to measure Lumens not because of ANY change in the physical characteristics of the light. (Like they did not know how to measure lumens before now)
Say What?
Seems like this is a marketing thing.
That said, if my L4 is really 100 Lumens then I guess I am happy.

 

[FlashInThePan]

Many have also suggested that Surefire conservatively measures their lights' output by *not* testing immediately when fresh batteries are inserted, but rather after xx minutes (20 or so?). This gives a much more realistic picture of the flashlight's true output (since it diminishes over time), even as it means that Surefire won't be able to market their flashlights at the higher lumen ratings!

Surefires are well known for being brighter than their stated lumens. Truly great flashlights. Pricy, but great. =)

 

[ACMarina]

Yeah, I'm not complaining..

 

[greenLED]

Many have also suggested that Surefire conservatively measures their lights' output by *not* testing immediately when fresh batteries are inserted, but rather after xx minutes (20 or so?). This gives a much more realistic picture of the flashlight's true output (since it diminishes over time), even as it means that Surefire won't be able to market their flashlights at the higher lumen ratings!

Haven't heard that mentioned on CPF. Could you provide me with a link so I can learn more? It seems pointless to me to wait 20 minutes before measuring output, especially in their regulated lights (output doesn't change); their incan lights don't have very long runtimes (around 1hr), so why choose to measure output at 30% of the runtime?

 

[bwaites]

Actually, and someone who knows better may correct me, but I understand that Surefire uses "Mid Point Voltage" or the mid point of useable voltage from the cells as used in the light to measure their ratings for incandescent, unregulated lights. Thus, Surefire is actually using something close to the "average" light output, vs. the best possible case, like many manufacturers.

In the LED based lights, I understand that Surefire uses the output from the lowest binned LED's that might be used. Thus, in the Lux5 based lights, a rating of 65 Lumens if a "T" bin might be used. It appears that Surefire feels confident that they have an adequate supply of "V" or better bins now and is able to advertise that minimum number of 100 lumens.

Surefire's incandescent lights are DEFINITELY under rated. The A2 is said to produce 50 Lumens, but has been independantly rated using an integrated sphere, at 79. The M6 is said to produce 500 lumens, but is probably closer to 630 on new cells. AND on top of that, Surefire actually uses "Torch Lumens" or light out the front, not "Bulb Lumens" which is the light produced by the lamp.

Most manufacturers that use Lumen ratings use the lamp outputs, not what goes out the front, and what goes out the front is only about 65% of bulb output.

Bill

 

[Numbers]

My question is -- If Surefire feels confident that they now have reliable supply of better binned Led's (which sounds entirely reasonable) why dont they just say that, instead of saying that they are better able to measure lumen output now (which sounds entirely UNreasonable) and that is what accounts for the new ratings?
I don't get it. Electronic products are improving every day what is their problem with saying that, if it is true (and not just a new marketing strategy)?

 

[bwaites]

Remember that what you are told by a customer service rep is not the official Surefire line.

Surefire has used an integrated sphere to measure it's lights output for a long time, they didn't suddenly become able to "measure lumens better", unless, of course, the integrating sphere they used was broken and all these readings we have been getting are low because of that!!!

Bill

 

[Mr Ted Bear]

In that SF has several integrating spheres, the idea that one might have been broken just doesn't fly.

The are mutiple reasons why the the lumen ratings have increased from 2005 to 2006. Higher flux leds for starters.

Second, better availablity. Before, they had to assume worse can senario, but with a consistant supply, they need not be as conservative with the numbers they put in print.

Third, lights are actually being driven at higher current levels than in the past.

There are a couple more reasons, but I wasn't taking note s :shrug:

 

[Fusion_m8]

Numbers - If the L4 is rated at 100 lumens in the 2006 catalogue, what is the L6 rated at??:thanks:

What explanation?
How did the surefire L4 go from 65 Lumens in the SF 2005 catalog to 100 lumens in the 2006 catalog? SF customer service told me it was because they are now better able to measure Lumens not because of ANY change in the physical characteristics of the light. (Like they did not know how to measure lumens before now)
Say What?
Seems like this is a marketing thing.
That said, if my L4 is really 100 Lumens then I guess I am happy.

 

[InfidelCastro]

A larger reflector will increase the lux usually, but does not affect lumen output. As I said earlier, lumens is total output of the light while lux is the 'concentration' of the beam.

I always thought of lux as "throw" while candlepower is more like the "lux" at a given range. Is that even true? This is probably all reletive. I know how easy it is to fudge numbers... even lumens.

 

[LEDcandle]

I always thought of lux as "throw" while candlepower is more like the "lux" at a given range. Is that even true? This is probably all reletive. I know how easy it is to fudge numbers... even lumens.

I'm not an expert on this and am basing my info from various sources and from reading in this forum

Anyway, here's an article by theledlight, it might shed some light on the topic :
http://www.theledlight.com/lumens.html

Apparently candlepower or candela is the bulb output measured at the bulb itself, and lumens is how much light is getting to the object you want to light.

But that doesn't seem consistent with what we know
:shrug: