Incorrect throw ratings

[Craig K]

I think a lot of flashlight companies say their LED flashlights throw further than they really do, has anyone else noticed this, for example Jetbeam say their M2S throws 650 meters where as I think it would only be able to throw around 450 meters.

It just seems to me companies are saying their lights throw further than they actually do.

 

[gcbryan]

I think a lot of flashlight companies say their LED flashlights throw further than they really do, has anyone else noticed this, for example Jetbeam say their M2S throws 650 meters where as I think it would only be able to throw around 450 meters.

It just seems to me companies are saying their lights throw further than they actually do.

On the one hand...what's new :) Exaggerated throw numbers, lumen numbers,run times, etc.

On the other hand the devil may be in the detail. How do they define throw? When the lux value gets down to moonlight levels?

 

[pjandyho]

They either derive the amount from pure calculations, or under very controlled environment and testing under ideal conditions. In real world usage many factors come into play on how much a light throws. Do note that throw factor is very much dependent on what you can see. The environment and humidity, your eyesight, surrounding light and even bright moonlight can affect your perception on throw. Having said that, I am not discounting the fact that there are manufacturers who hyped up the numbers for the sake of marketing. High number always sell better.

 

[kramer5150]

it also completely depends on what they are illuminating at that distance. A white reflective street sign in complete darkness will reflect an E01 back over 50+ yards. But we all know its not even close to that.

 

[samgab]

How do they define throw? When the lux value gets down to moonlight levels?

The ANSI/NEMA FL1 standard, which I wish all quality light producers would adopt is:

For beam distance:
-The distance from the device at which the light beam is 0.25 lux.
0.25 lux is approximately the equivalent of the light emitted from the full moon "on a clear night in an open field".
Results are to be reported in Meters.
Method:
Place the luxmeter at a test distance of either 2 or 10 or 30 meters from the lens of the device to be tested. Use the luxmeter to identify the brightest point of the beam pattern and record the highest indicated value (within 30s to 2 min of turning on the device).
Then calculate using Inverse Square Law formula:
√ (peak beam intensity (cd)/0.25 (lux)) = Max Beam Distance (m).

 

[rmteo]

You left out the part where Peak Beam Intensity = Surface intensity * Square of the Distance.

 

[samgab]

You left out the part where Peak Beam Intensity = Surface intensity * Square of the Distance.

Yes, that's right.

 

[Shooter21]

of course they exaggerate throw distance. In reality with most lights you get about 50 yards of useful illumination.

 

[ScaryFatKidGT]

My Fenix lights and Mag XL50 do what is rated. My PD31 and XL50 both say 140-145 meter and id say they do that. They both are pretty throwy with smooth reflectors.

 

[rmteo]

The thing with throw (at least as defined by the ANSI/NEMA standard) is that it is fairly easy to confirm/verify. All you need is lux meter and one simple measurement. I use the following derived formula for convenience:

Throw (aka distance where lux = 0.25) = 2 * square root(lux reading) * measurement distance

You can use whatever measurement distance (and/or measurement units). However, as you have mentioned, to comply with the standard the measurement should be done at 2 or 10 or 30 meters.

 

[Craig K]

Yeah I just think the flashlight companies really exaggerate the throw of their LED lights by a long long way, I mean do any LED flashlights really throw any further than say 400 meters?

 

[jhc37013]

Yeah I just think the flashlight companies really exaggerate the throw of their LED lights by a long long way, I mean do any LED flashlights really throw any further than say 400 meters?

Sure they do but they are just really large like the SR90 and TK70. Although I have tested my SR51 at over 400m and I think it does a good job at 400, I can make out a tree line at that distance so I guess it really goes back to how you interpret throw.

 

[pjandyho]

A little off topic here since the original post is about whether manufacturers inflate their throw numbers, but I always felt that light that throws far are IMHO useless. Lights like SR90 are too huge for lugging around and offers very very limited uses other than throw for long distance subject and provided our eyes could distinguish details that far out. How much details could one distinguish pass the 200 yards mark? Not much, especially on a night with high humidity. Maybe for trail spotting but again it is too heavy to lug around on a hiking trip. Already I find the Surefire UB3T too cumbersome for extended walking.

 

[jhc37013]

Your right pjandyho humidity can just kill throw, I sometimes feel like I'm trying to see through fog on really humid nights. Maybe manufactures throw ratings should come with a * Throw will vary depending on humidity.

 

[Walterk]

It just seems to me companies are saying their lights throw further than they actually do.

The ANSI definition for throw is based on the distance the beam measures 0.25 lux.
0.25 Lux is hard to use unless you are in the middle of the desert on a clear and overcast night.
For real life 1.0 lux is much more meaningful. The international standard for defining throw for searchlights and high intensity lights is based on that value. For a reason.

Its questionable how manufacturers obtain there numbers. Is it the highest measurements out of a batch of 20 lights with handpicked bulb and batteries and reflector?
Or is it measured by a unbiased third party?
Or, and that s what I think is best practice in the flashlight industrie:
We dont want to spend on testing and feel its not needed because we houestly think we can calculate for our clients:
We use this led 'X', with this driver current consumption 'Y', and a reflector this diameter 'Z' , losses neglected in calculations.
So the 'calculated' or no 'somewhat guessed' output would be 'P' Lumen, 'Q' throw and 'R' runtime.

Still think, any standardized ratings are useful.
Give me a list of lights with their throw, lumen and runtime ratings and I know what light I would like to see best in the shop.

 

[gcbryan]

Your right pjandyho humidity can just kill throw, I sometimes feel like I'm trying to see through fog on really humid nights. Maybe manufactures throw ratings should come with a * Throw will vary depending on humidity.

I basically agree with you for many "extreme throw" lights but there is another aspect. Throw is lux on target. So a thrower at shorter ranges is also the brightest light and provides more detail.

If you live on a farm and want a light to shine on part of your property a light with a XM-L may illuminate the part of your property around your house. The thrower used on that same part of your property that was illuminated by the XM-L will illuminate a smaller chunk but it will provide more detail (because it's brighter). It doesn't have to all occur at 1,200 feet.

 

[samgab]

I don't mind what amount of lux is chosen for the standard, I just like that it gives an equal measuring stick to compare one with another, if only they would all use said measuring stick... I think going forward I'm only going to buy flashlights from manufacturers that use the ANSI/NEMA FL1 standard.
There's a similar thing with audio systems, with total power output RMS at X.XX% THD... It varies depending on how the manufacturer decides they're going to spin the numbers.

 

[2100]

0.25 Lux is hard to use unless you are in the middle of the desert on a clear and overcast night.
For real life 1.0 lux is much more meaningful. The international standard for defining throw for searchlights and high intensity lights is based on that value. For a reason.

Ahh...finally somebody who is talking something really useful. That is right, 1 lux at the target. It is also quite easy. Eg, 400k lux light @ 1m, throw = sq rt of that = 632m. Easy.

Searchlights... Check out the PDFs...play with the lux and PBCP with the above formula.
http://www.francis.co.uk/technical.asp

You can easily see past 400m, even past 8km (I just done that last week somewhat). My country has pretty high humidity 90% of the time at night (it is usually 100% in the early hours). The fact that you are not seeing stuff past 200m, 400m for LEDs is simply they are not powerful enough. I have several lights which go past 1 million lux @ 1m and also with enough lumens so having a super narrow beam is not critical.

Some people mistake that for throw only lux is important. To see a spot reflected back well of course that is important. But for IDing something, for eg a big marine vessel 3km away well you'd need both lux + lumens. This is because that guarantees that instead of a 0.5 deg beamwidth which illuminates only a portion of a supertanker, you'd ID the supertanker as a whole entity with a 1.5 deg beam. And to get enough light into that 1.5 deg beam you'd need lumens as well.

Number 2 point, is that the object that you are trying to ID at say 1km distance. Obviously you are not going to see even a car well at 1km unless you search for it in detail. Forget about spotting a person unless he is wearing fluorescent orange standing in front of a treeline. 1km objects = stuff like house, skyscraper, 50 foot marine vessel etc.

Commercial lights do not have ANSI/what NEMA standards, not that I have seen one on the spec sheets.

Hope that makes sense. :D

PS, I am not dissing lights like SR90, TK70, DEFT or even customs with 250k CP. My TK70 copy is due to arrive next week from Hong Kong.

 

[kyhunter1]

Something to think about, maybe the light will illuminate reflective targets well past your eyes percieved throw range of your beam. I have noticed that with a few of my personal lights before. That could be somewhat misleading, but not completely dishonest either if they are quoting specs based on reflective distance only. Malkoff accurately says that a M61 will illuminate objects to 350 feet. That does not mean that the beam will be bright and well defined enough to see small specific details at that distance.

 

[pjandyho]

Ahh...finally somebody who is talking something really useful. That is right, 1 lux at the target. It is also quite easy. Eg, 400k lux light @ 1m, throw = sq rt of that = 632m. Easy.

Searchlights... Check out the PDFs...play with the lux and PBCP with the above formula.
http://www.francis.co.uk/technical.asp

You can easily see past 400m, even past 8km (I just done that last week somewhat). My country has pretty high humidity 90% of the time. The fact that you are not seeing stuff past 200m, 400m for LEDs is simply they are not powerful enough, just that and nothing more. I now have 3 lights which go past 1 million lux @ 1m and another stuck at 800k. (actually my DX sort of under reads by about 10-20% compared to the good ones)

PS, I am not dissing lights like SR90, TK70, DEFT or even customs with 250k CP. My TK70 copy is due to arrive next week from Hong Kong.

I do agree that the brighter the light the further you see but I think you are missing the point. The point here is that our human visual perception is very limited. Seeing and making out a form is one thing, but being able to discern details of what you see is another. We can see a huge tree at a distance of 1km but other than a huge tree standing there, can we discern more details than that? No. I am vey certain about that since my eyesight is perfect. If we could all discern minute details pass the 8km range as what you have stated, we would all be bionic men and women and there is no need for visual enhancement optics like a telescope, or binocular. Maybe you can, but I definitely can't make out fine details pass 8km as what you have said.