Range of a flashlight
Question to Knivesandtools:
The PD32 indicates it shines up to a distance of 141 metres. Is that realistic? And if not, what is a realistic value?
Answer of Knivesandtools:
If you want to know how far a lamp shines, you must first define what the minimum light output is for you to still see anything. The light of a torch shines endlessly far but it becomes progressively weaker.
According to the ANSI standard for torches the minimum quantity of light to still be able to see something is 0.25 lux. On that basis, many manufacturers, including Fenix, currently indicate how far a torch shines. Check that it indicates whether the ANSI standard is applied.
Regarding the indication: 0.25 Lux is very little light. In clear weather you can distinguish contrasting objects like a black door in a white building perfectly at 0.25 lux, but in less contrasting environments you need more light and if the weather is misty the range of a torch is limited anyway.
Regarding the ANSI indication: one quarter of the indicated distance is a more realistic distance (you then have some 4 Lux light output). For the PD32 that was the subject of this question, it is approximately 35 metres.