Jim-Alex:
"You are probably correct on the eye perceiving only
"so much" brightness, then your lens shuts down quite a bit."
Actually that isn't quite what I meant. What I was trying to say was that I think eyesight brightness perception may be "logarithmic", like human ears are.
For example, for a car stereo, in order to make it sound _twice_ as loud, you actually need _ten_ times as much power, not _twice_ the power. If it only took twice the power to make it sound twice as loud, then it would be linear. Since it takes ten times as much power, it's logarithmic. Here's a URL that briefly talks about this: http://www.iitap.iastate.edu/numaps/poudel/decibel.html
(The reason you don't need to turn the volume control up 10 times to make it twice as loud is because the volume control itself is a logarithmic control, not a linear one like a toaster's darkness control).
So in terms of flashlights... I was thinking that maybe it takes more than twice the lumens for something to seem twice as bright. I don't know if it's a "base 10" logarithm (meaning it takes 10 times the lumens), or "base 5", or some other base, but it appears to be non-linear.
Of course, I could just have mutant eyeballs
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To answer your question, I perceived the brightness from behind the light rather than having someone flash the light in my eyes. My momma told me not to look into bright lights
"You are probably correct on the eye perceiving only
"so much" brightness, then your lens shuts down quite a bit."
Actually that isn't quite what I meant. What I was trying to say was that I think eyesight brightness perception may be "logarithmic", like human ears are.
For example, for a car stereo, in order to make it sound _twice_ as loud, you actually need _ten_ times as much power, not _twice_ the power. If it only took twice the power to make it sound twice as loud, then it would be linear. Since it takes ten times as much power, it's logarithmic. Here's a URL that briefly talks about this: http://www.iitap.iastate.edu/numaps/poudel/decibel.html
(The reason you don't need to turn the volume control up 10 times to make it twice as loud is because the volume control itself is a logarithmic control, not a linear one like a toaster's darkness control).
So in terms of flashlights... I was thinking that maybe it takes more than twice the lumens for something to seem twice as bright. I don't know if it's a "base 10" logarithm (meaning it takes 10 times the lumens), or "base 5", or some other base, but it appears to be non-linear.
Of course, I could just have mutant eyeballs
---
To answer your question, I perceived the brightness from behind the light rather than having someone flash the light in my eyes. My momma told me not to look into bright lights
