brightness

[RichD]

I was shopping for a flashlight recently, and naturally
noticed a trade-off between size/compactness and brightness.
The devices range up to 500 Lumens.

Human perception is logarithmic. So I wonder, at what
point, measured in Lumens, does apparent brightness
level off? For instance, imagine you're in a dark place,
and you want to blind an adversary. How many Lumens required?

I seek the brightest lamp reasonable, while at the
same time portable; pocket or belt carry

--
Rich

[Phil Hobbs]

Post by RichD
I was shopping for a flashlight recently, and naturally
noticed a trade-off between size/compactness and brightness.
The devices range up to 500 Lumens.
Human perception is logarithmic. So I wonder, at what
point, measured in Lumens, does apparent brightness
level off? For instance, imagine you're in a dark place,
and you want to blind an adversary. How many Lumens required?

Lumens are like watts---they measure the total amount of visible light.
A good 100W incandescent bulb circa 2012 put out 1690 lumens. That's a
whole lot for a flashlight.

For a narrow-angle applications, you care more about lux (lumens/sq
metre). 1000 lux is a nice number for reading a book, but 5000 is better
for an old guy doing close work. ;)

For incapacitating somebody, you're much better off with an 8-D-cell
Maglite, know wha' I mean?

Cheers

Phil Hobbs

[RichD]

Post by Phil Hobbs

Post by RichD
I was shopping for a flashlight recently, and naturally
noticed a trade-off between size/compactness and brightness.
The devices range up to 500 Lumens.
Human perception is logarithmic. So I wonder, at what
point, measured in Lumens, does apparent brightness
level off? For instance, imagine you're in a dark place,
and you want to blind an adversary. How many Lumens required?

Lumens are like watts---they measure the total amount of visible light.
A good 100W incandescent bulb circa 2012 put out 1690 lumens. That's a
whole lot for a flashlight.
For a narrow-angle applications, you care more about lux (lumens/sq
metre). 1000 lux is a nice number for reading a book, but 5000 is better
for an old guy doing close work. ;)

The packages include the FL1 standard, but I don't know how to interpret
that. One of the specs displays a light cone, and e.g. '95 ft.' This indicates lux?

Then there's a picture of a light beam reflecting from the floor ...?

Post by Phil Hobbs
For incapacitating somebody, you're much better off with an 8-D-cell
Maglite, know wha' I mean?

One of those police torches - not too convenient for routine carry -
probly nice self-defense gadgets though - "It's a tool, not a weapon, officer!"

--
Rich

[Phil Hobbs]

Post by RichD

Post by Phil Hobbs

Post by RichD
I was shopping for a flashlight recently, and naturally
noticed a trade-off between size/compactness and brightness.
The devices range up to 500 Lumens.
Human perception is logarithmic. So I wonder, at what
point, measured in Lumens, does apparent brightness
level off? For instance, imagine you're in a dark place,
and you want to blind an adversary. How many Lumens required?

Lumens are like watts---they measure the total amount of visible light.
A good 100W incandescent bulb circa 2012 put out 1690 lumens. That's a
whole lot for a flashlight.
For a narrow-angle applications, you care more about lux (lumens/sq
metre). 1000 lux is a nice number for reading a book, but 5000 is better
for an old guy doing close work. ;)

The packages include the FL1 standard, but I don't know how to interpret
that. One of the specs displays a light cone, and e.g. '95 ft.' This indicates lux?
Then there's a picture of a light beam reflecting from the floor ...?

Post by Phil Hobbs
For incapacitating somebody, you're much better off with an 8-D-cell
Maglite, know wha' I mean?

One of those police torches - not too convenient for routine carry -
probly nice self-defense gadgets though - "It's a tool, not a weapon, officer!"
--
Rich

The ones all the rent-a-cops carry. Billy clubs are illegal, but
flashlights are OK.

Cheers

Phil Hobbs