This is my first post and I am very new to the technical side of torches, and I am sorely aware of how ignorant I am. Please forgive what is most likely a stupid question…
I recently bought BLF’s NW FW1A as I am chasing the best budget small pocket thrower I can get. The throw is stated as being 370m but when I walk at night on a bush track I feel I can only illuminate trees to about 150m.
I’ve tried searching for an answer but my head is spinning with (to me) what amounts to a lot of confusing Information.
Can someone point me in the direction of info that an ignoramus like me can understand?
Welcome to BLF! The stated specification is based on how much light is on the target at 370 meters. That may possibly be very different from the amount of light that is on your trees at 150 meters.
A quick google gives some explanations here . But basically, “throw” is calculated based on beam intensity, and is the distance at which the beam should theoretically provide 0.25 lux. Since one “lux” is one lumen per square meter, 0.25 lux is 0.25 lumens per square meter. It’s about the light level that you’d get shining a 0.25-lumen flashlight (or, more realistically, the moonlight mode of a flashlight) from a couple feet away at something.
All this is to say that the ANSI throw standard is rather generous. You’re most likely not going to be able to see 0.25 lux when you’re a couple hundred meters from something - especially when there’s other light near you that’s much brighter (like the flashlight’s own spill). In my experience, a usable range tends to be… something like half the rated throw. But this varies from light to light, as well.
Practical viewing distance is about ¼ to 1/3 the FL1 distance given – assuming the manufacture’s specs are not embellished or made up as is often the case.
