Beam Distance

Just wondering if there is a standard for quoted "beam distance" that you see from different light companies?
If there isnt a standard guide it makes it very hard to compare...also "effective" distance is a personal opinion i guess.
For example...while i love my MD2 and Maglite dropin from Gene..and after doing hours of testing here on the farm at measured distances...effective distances to me would be MD2 300ft and the Mag dropin 660ft.Past that you would see reflections from animals eyes etc but very little else "effectively" IMO
Any thoughts?

Yes, there is a standard. ANSI FL1 defines beam distance as the max range at which the most intense portion of the beam puts .25 lux on target. This number was chosen because an average moonlit night provides a uniform .25 lux.

Candela is another way to define it. If you know the candela rating, you know the beam distance...it is just another way to measure the same thing.

You are correct that effective distances are highly subjective. A quarter lux, especially at long range, is not enough for you to see much detail. Generally, I divide the ANSI range number in half. This is the distance at which the light will put 1 lux on target...a more realistic number in my experience. But any standard is arbitrary...and it is very easy to convert with a little basic math. The important thing is that it allows you to compare range/intensity at a glance.

If it's anything like the ANSI FL1 lumen/runtime standards, then the rules are wide enough to drive a truck through and each manufacturer will employ its own levels of conservatism/exaggeration, not to mention the outright lies. I'm not referring to FleaBay or DX junk either - I find a CPF-favorite brand to be exaggerating by double on a lumen-hrs basis.

As mentioned, yes, the ANSI standard is what they use to rate their throw, and, as mentioned, can be used to compare lights, but, typically NOT to know the distance at which you might see something per se.

So, they might give the range in feet (Gives a larger "Number"), or meters (More related to the involved units of measure), and, they might give the throw in lux at one meter (Some list at other ranges, but those are NOT ANSI compliant), and some might give the light's cd (Candela - Which is the interpolated lux at one meter).

As light intensity drops with distance according to the inverse square law, at half the range, its 4x brighter, or, at double the range, its 4x DIMMER, and so forth.

As mentioned, many of us consider 1 lux to be a more realistic minimum USEFUL range for a light at distance (Close up, you CAN see ok at 0.25 lux, which is about an average moonlight level. (Not a full moon, average)

For perspective, there is no one "correct" range for a light to see everything...if an object is darker or with less contrast, etc, it is proportionally harder to see, and more light is needed.

For example, at 200 meters, my guys can shoot a white paper target (Man torso sized) with ~ 1 - 5 lux on it, but can't even FIND a rusty steel plate (man torso sized), sometimes even with 15 lux to see it with. (Both facing them, as targets...)


So, depending on what YOU want to be able to see, you will need different amounts of light than someone else might.


If you have a rating for the two example lights you listed, you can then post the meters they are rated to, and compare that to your experienced based ranges for them...and we can then calculate the lux that worked for YOU.

You can then use that lux as a spec to know what lux level you need if choosing another light.

IE: Your light is working at 300' for you, lets call that 90 meters to make the math easier.

What ever lux worked at 90 meters, you'd also want for say 200 meters.


Same for the 660' (~ 200 meters). Whatever you found usefil at 200 meters, is what you'd want at say 400 meters or whatever range you actual need to see at, that the above lights are not reaching for you.

IS THERE a range you need/want to be able to see at? You'd plug THAT into the above.