We all know that green lasers appears brighter than the others,but was that ever measured?What is the proportion of brightness between lasers of same real power at 405nm,473nm,532nm and 650nm?I think I've read somewhere that green lasers appears to be 8 times brighter than red lasers to the eye.
LPF Donation via Stripe | LPF Donation - Other Methods
Links below open in new window
ArcticMyst Security by Avery
Brightness by wavelength?
- Thread starter GamerBR
- Start date
diachi
0
- Joined
- Feb 22, 2008
- Messages
- 9,700
- Points
- 113
Re: Apparent power by wavelength?
Green lasers aren't more powerful, that seems to be a common mis conception .
They just appear brighter because your eye is most sensitive to the green part of the spectrum.
Diachi
Green lasers aren't more powerful, that seems to be a common mis conception .
They just appear brighter because your eye is most sensitive to the green part of the spectrum.
Diachi
diachi
0
- Joined
- Feb 22, 2008
- Messages
- 9,700
- Points
- 113
Re: Apparent power by wavelength?
ok ....
ok ....
Re: Apparent power by wavelength?
Ok,as you didn't understand at first let's make it clear to everyone else,I mean get lasers with different wavelengths with the same real power,how much more visible will green be comparing to red,violet to red,red to violet,etc.
Ok,as you didn't understand at first let's make it clear to everyone else,I mean get lasers with different wavelengths with the same real power,how much more visible will green be comparing to red,violet to red,red to violet,etc.
Switch
0
- Joined
- Dec 9, 2007
- Messages
- 3,327
- Points
- 0
Re: Apparent power by wavelength?
By "apparent power" you mean brightness.Power is power, it's a physical measure.Brightness is how our eyes percieve it.So because our eyes are more sensitive to green , green is brighter and also more dangerous.
There was a graph somewhere that you could've used to see exactly how many times a wavelength is brighter than another, but I don't know how accurate it is.
Yeah, here it is.As you may know, during the day, the brightest wavelength is 555nm.But in low light situations, scotopic vision kicks in , and 505nm is the brightest.
By "apparent power" you mean brightness.Power is power, it's a physical measure.Brightness is how our eyes percieve it.So because our eyes are more sensitive to green , green is brighter and also more dangerous.
There was a graph somewhere that you could've used to see exactly how many times a wavelength is brighter than another, but I don't know how accurate it is.
Yeah, here it is.As you may know, during the day, the brightest wavelength is 555nm.But in low light situations, scotopic vision kicks in , and 505nm is the brightest.
Attachments
daguin
0
- Joined
- Mar 29, 2008
- Messages
- 15,989
- Points
- 113
Re: Apparent power by wavelength?
That's why I said apparent power.[/quote]
So what you are asking is how much "brighter" it will look to "me"? There are so many extraneous and confounding variables in that "test" to render it completely worthless.
Peace,
dave
GamerBR said:
That's why I said apparent power.[/quote]
So what you are asking is how much "brighter" it will look to "me"? There are so many extraneous and confounding variables in that "test" to render it completely worthless.
Peace,
dave
Re: Apparent power by wavelength?
I think the confusion has to do with you using the term apparent power. If all the lasers are the same power, then the power has absolutely nothing to do with how well you can see each one. I think the term you want is apparent brightness. Diachi has the correct answer to your question though. The human eye is most sensitive to the green part of the spectrum. In addition to that, the shorter wavelengths are also scattered more by the air than longer. This also makes the green more visible than red.
I think the confusion has to do with you using the term apparent power. If all the lasers are the same power, then the power has absolutely nothing to do with how well you can see each one. I think the term you want is apparent brightness. Diachi has the correct answer to your question though. The human eye is most sensitive to the green part of the spectrum. In addition to that, the shorter wavelengths are also scattered more by the air than longer. This also makes the green more visible than red.
Switch
0
- Joined
- Dec 9, 2007
- Messages
- 3,327
- Points
- 0
Re: Apparent power by wavelength?
That's why I said apparent power.[/quote]
So what you are asking is how much "brighter" it will look to "me"? There are so many extraneous and confounding variables in that "test" to render it completely worthless.
Peace,
dave
[/quote]
Yeah, I'm not sure who made the graph , but I would guess it refers to a perfectly healthy eye. :-/
daguin said:
That's why I said apparent power.[/quote]
So what you are asking is how much "brighter" it will look to "me"? There are so many extraneous and confounding variables in that "test" to render it completely worthless.
Peace,
dave
[/quote]
Yeah, I'm not sure who made the graph , but I would guess it refers to a perfectly healthy eye. :-/
Switch
0
- Joined
- Dec 9, 2007
- Messages
- 3,327
- Points
- 0
Re: Apparent power by wavelength?
So many people don't understand that "Power" is a physical measure , it has it's own solid definition , formula (P=E/t) and unit (Watt) and that it doesn't mean "burning power" or "brightness" and it's not apparent nor relative like burning power and brighness are.That is the power that we measure and rate our lasers in.It doesn't mean "destructive force" or whatever , it means exactly how many Joules the laser is spewing out the apperture every second, and that's how many Watts it has. :
climbak said:
So many people don't understand that "Power" is a physical measure , it has it's own solid definition , formula (P=E/t) and unit (Watt) and that it doesn't mean "burning power" or "brightness" and it's not apparent nor relative like burning power and brighness are.That is the power that we measure and rate our lasers in.It doesn't mean "destructive force" or whatever , it means exactly how many Joules the laser is spewing out the apperture every second, and that's how many Watts it has. :
Re: Apparent brightness by wavelength?
Ok,I edited the topic,I used apparent power as a litteral translation that make sense in my language.Anyway the graph seems to confirm what I read,that green lasers appears 8 times brighter than red lasers at the same power.
Ok,I edited the topic,I used apparent power as a litteral translation that make sense in my language
.Anyway the graph seems to confirm what I read,that green lasers appears 8 times brighter than red lasers at the same power.Re: Apparent brightness by wavelength?
I agree. Maybe that should be added to the FAQ.
Switch said:So many people don't understand that "Power" is a physical measure , it has it's own solid definition , formula (P=E/t) and unit (Watt) and that it doesn't mean "burning power" or "brightness" and it's not apparent nor relative like burning power and brighness are.That is the power that we measure and rate our lasers in.It doesn't mean "destructive force" or whatever , it means exactly how many Joules the laser is spewing out the apperture every second, and that's how many Watts it has. :
I agree. Maybe that should be added to the FAQ.
VW
0
- Joined
- Mar 1, 2008
- Messages
- 577
- Points
- 0
Re: Apparent brightness by wavelength?
Faraday + Maxwell = win...
Faraday + Maxwell = win...
Switch
0
- Joined
- Dec 9, 2007
- Messages
- 3,327
- Points
- 0
Re: Apparent brightness by wavelength?
Though I don't know how correct "apparent brightness" is, I mean, isn't brightness always apparent? It might be redundant.... :-/
Anyway, well if the graph is good you'll also be able to compare any wavelengths to any other wavelengths.And it's probably true, the DX30 is definetly brighter than a ~150mW red.But then again , I haven't tested either of them, just estimating 30 and 150mW on full batteries. :-/
GamerBR said:Ok,I edited the topic,I used apparent power as a litteral translation that make sense in my language
Though I don't know how correct "apparent brightness" is, I mean, isn't brightness always apparent? It might be redundant.... :-/
Anyway, well if the graph is good you'll also be able to compare any wavelengths to any other wavelengths.And it's probably true, the DX30 is definetly brighter than a ~150mW red.But then again , I haven't tested either of them, just estimating 30 and 150mW on full batteries. :-/
daguin
0
- Joined
- Mar 29, 2008
- Messages
- 15,989
- Points
- 113
Re: Apparent brightness by wavelength?
You "see" that in this graph?
:-? :
Peace,
dave
GamerBR said:
You "see" that in this graph?
:-? :Peace,
dave
Switch
0
- Joined
- Dec 9, 2007
- Messages
- 3,327
- Points
- 0
