Help me understand throw distance and rating...

I’m reading up on thrower lights and the rating is astounding.
Some throw over a kilometer.
How can anyone even see what’s there whether there’s light or not?
I can’t see a person that far even under the Sun.
Forget 1000m, it’s hard to see anything half of that during the day and make a sense unless the person is wearing bright contrasting color clothing.
Are those long throwers supposed to be used with a binoculars or something, like in dedicated SAR situation?

Well I’m not a mathematician or expert, so all you experts correct me if I’m wrong, but the way they measure visible light over a distance is candela. The higher the candela number, the more intense the light, and therefore the higher the “throw.” The actual number is based on the light source distance from the light sensor in meters (measured in lux) which is coverted to candela then to distance by using math; candela ÷ .25 then sq. route.

As to being visible at distance, I think the generally accepted standard for visible light in candelas is equivalent to a full moon on a dark night-or around 1 lumen at xxx meters. In reality, you may be barely able to notice the light at that distance.

The ANSI throw is the distance where the intensity on the target is 0.25 lux IIRC, that’s only equivalent to moonlight. The effect is that throw numbers are 2x or 3x the actual effective range because you need more than moonlight to see anything useful, but at least they are consistent. Being consistent is still an improvement over the previous situation where everybody used their own definition.

As far as visual throwing distance, one way is to pick a far away large target during the day, like a hill or a building, then see if you can see it lit up with your thrower at night, assuming it’s not lit up by something else.

For example, see here:

If that doesn’t work, then you need a second person standing at the target site, both of you with cell phones, and careful aiming…“can you see it now” type thing, and possibly a light meter.

I’m kinda hooked on throwers and its funny the calculated throw is not very visible at 1000 meters even though it is suppose to throw 2400 meters. So all the ads are to sell lights, they almost never deliver on distance or lumens. However, to hold a light that throws good is fun. Does anyone really need one ? Maybe a few. I’m just amazed how powerful they are compared to lights that were available when I was younger and could use them camping and fishing.

So let’s assume a thrower can really throw 1000 meters but what’s the point?
There could be a mountain lion or a bear and even if the light reaches there, we can’t see that far to avoid going that route.
What’s our eyes capacity when looking for things at night?
250 meters? 300 meters?
Anything more is just numbers as it doesn’t matter if we can’t discern what we are lighting up.

Heres my take on it the higher the rating of throw gives MOAR intense light at closer ranges. Lets use the BLF GT90 as an example, its rated at roughly 1.8m~ CD which is around 2600~ meters throw so at your proposed 300 meters the target would be lit up like day and you would be able to discern anything as something in the target zone.

Another example would be police helicopters using a spotlight, generally they fly around the 10,000 feet range in the cities which is around 3km or 1.9 miles in the air and they can discern targets from that range with a spotlight.

Numbers sell flashlights, bottom line. Our eyes can’t see things illuminated with 1 or .25 lumens at 1000m so as yes, anything over say 400m unaided is purely ‘what if’ advertising. It takes huge amounts of power and high intensity to visibly illuminate items at thousands of feet away (like 10kw short arc spotlights). If I can light up a car at 400m then that’s awesome, but it takes a stout thrower for that.

Not if you go LEP. :wink: they are pretty nifty and light things up at insane distances while being very pocket able.

Isn’t there a law against using it?
Specially near airports?
It can reach planes and helicopters.
If by mistake it hits someone’s eye in the sky, it’ll be hard to explain authorities that you were just testing your new gadget.

LEPs and lasers are entirely different and the range of a laser far surpasses anything a flashlight will ever produce. A good LEP by specs may reach helicopter flight range which is around 10000 feet but even the best LEP’s are maybe around what an MF05 can produce, but a laser is an entirely different ballgame it would be obvious that you were aiming at them as they have light indicators that are clearly visible.

Here is a breakdown of how intense basic laser pointers are in ranges. Also why would you go test anything near an airport…… thats just asking for trouble !

This does not directly pertain to your question, but it is worth mentioning to consider what you are using it for. Most often I am checking for animals with the thrower since I carry a more floody light for walking. And the animals’ eyes glow when illuminated at a greater distance than other objects. So the useful distance is relative to your purpose for carrying a thrower. Just a thought. Enjoy your lights!

Nothing specific, just general use around the home and occasional camping and hiking.
Reading up on throwers to see what fits the bill and collect info.

Just last week, my neighbor’s cat came to our backyard and they were looking for it with a flashlight over the fence.
I saw light flashing in my backyard so went out to see what’s going on
They had a big orange plastic flashlight that was a floody light and not bright enough to light up my backyard.
I turned on my Modoao and looked around. It has good spill with very bright center.
I saw the cat in my Raspberry bush around 30 feet away probably looking for voles.
It got startled and jumped the fence in to another neighbor’s backyard.

This flashlight can light up the tree across the street behind my backyard nicely that’s probably 130 feet away.
I may buy a good brand thrower to see what the fuss is about probably after testing current flashlights out in the hiking trail when I get a chance.

My MF04 can light up 1.2 miles.
The funny part is that I can see at that distance.
I can’t identify if it’s a man or a woman.
But if people are moving, I can see where they are going.
They most not like me at the other side, but who’s gonna get me.


(And I have binoculars)

What led do you have in your MF04 ?
I just ordered another one to modify.

What led do you have in your MF04 ?
I just ordered another one to modify.

I have the factory emitter.
Not that I don’t want to modify ’em.
It’s my hands. I have destroyed everything I touch.