laser brightness?

[deathstarlaser]

ok so for laser brightness,,does the brightness of the laser dot double exactly with the mw? as 100mw green is 100x a 1mw green,,,,10mw is 2x 5mw? ect.... the laser brightness calculator says that but many say that part is not accurate.. and is it the same for the beam?

 

[Lase]

No perceived brightness is not linear.

Maybe rather than just necro'ing old threads, try reading them.

Lase

 

[deathstarlaser]

so how does it increase then? they did not come up with a clear answer...just how to calculate Raleigh scattering for different colors..

 

[TheReddish]

532.0605794nm=602.2082543 lumens per W is the best I can do in short notice. also here is good thread for ya http://laserpointerforums.com/f44/new-tool-calculate-relative-brightness-wavelengths-nm-61238.html

 

[Lase]

so how does it increase then? they did not come up with a clear answer...just how to calculate Raleigh scattering for different colors..

Read This

That's the best answer that I have seen so far and covers laser brightness by colour. There is no real answer to your question as once a laser reaches a certain power the dot becomes far too uncomfortable to look at and your perception is skewed. This power level is different based on the colour of the laser and your own eyesight.

There are also links there to another thread where madmacmo explains the mathematics

Lase

 

[deathstarlaser]

ok thanks where does that kind of calculation come from?

 

[TheReddish]

to be honest its all based on CIE tables if you look at the link I provided RHD has made a tool you can use and can also factor in Raleigh scattering.

 

[Lase]

ok thanks where does that kind of calculation come from?

References are linked. But you seem to have a problem with reading.

Ref: Luminous Flux

Google Wavelength Perception Spreadsheet

Lase

 

[Sigurthr]

Comparing perceived brightness of a single wavelength the inverse-square law applies when talking about beam brightness, so 4x the power = 2x as bright. Again, this is beam only, not the spot on a surface.

 

[deathstarlaser]

ok those are good answers ...lol and sorry at first my computer was not letting me see the links for some reason

 

[Cyparagon]

Percent brightness increase ≈ √(P2/P1)×100

 

[John Capelo]

Using rhd's brightness calculator, why does it show that the brightness of say, a 60mW beam is twice that of a 30mW beam? shouldn't it only be sqrt(2)? since the power is 2x, the square root of that

 

[TheReddish]

It may be calculating your Raleigh scattering if you are selecting beam.

 

[Lase]

Using rhd's brightness calculator, why does it show that the brightness of say, a 60mW beam is twice that of a 30mW beam? shouldn't it only be sqrt(2)? since the power is 2x, the square root of that

rhd's Calculate Relative Perceived Brightness tool isn't 100% yet. Last I remember he was looking for something more reliable than the CIE tables to base his calculations on. There was also talk about accounting for photopic and scotopic vision.

Edit: Here's the thread on it (last post on 05-26-2011)

Lase

 

[Atomicrox]

Percent brightness increase ≈ √(P2/P1)×100

What's the theoretical basis for this formula? People use it all the time but I couldn't figure where it comes from.

 

[Cyparagon]

The mark-1 eyeball. Brightness is a perception, and thus has no exact quantitative unit. It's just a formula we've agreed works well enough.