Brightness ratio between colors

[SmurfTacular]

What is the brightness ratio between all the colors of the spectrum? For example, I know that a 200mW 660nm (red) is just as bright as a 4mW 532nm (green). How bright is a 405nm (violet) compared to a 532nm, or a 593.5nm (yellow-orange)?

 

[Moptsp]

I don't know how to find the exact ratio, but I would imagine you could start by looking into how the retina picks up on light and find out the ratio at what x color is absorbed/reflected.

I don't believe 660nm is as bright to the eyes as 532nm though.

-Moptsp

 

[pullbangdead]

Via the DIY Group page, and google:

 

[ProjMan]

What is the brightness ratio between all the colors of the spectrum?

Current best knowledge in this area comes from:

Sharpe, L. T., Stockman, A., Jagla, W., & Jägle, H. (2005). A luminous efficiency function, V*(λ), for daylight adaptation. Journal of Vision, 5(11):3, 948-968, Journal of Vision - A luminous efficiency function, V*(λ), for daylight adaptation, by Sharpe, Stockman, Jagla, & Jägle

The data you want are in table 3. These figures are the best available but are not absolute gospel as individual response varies.

For example, I know that a 200mW 660nm (red) is just as bright as a 4mW 532nm (green). How bright is a 405nm (violet) compared to a 532nm, or a 593.5nm (yellow-orange)?

By my math (not necessarily correct), 4mw of 532nm is equivalent in brightness to 737mw of 405nm, 5mw of 593nm, and 59mw of 660nm. 200mw of 660nm equates to about 14mw of 532nm.

 

[Jaseth]

405nm is not really possible to figure out - it depends on the particles in the air, the surface the dot is on, your eyes and how dark it is.
According to most graphs, blu-ray should basically be invisible, but in several cases it will actually appear more visible than both 660nm and 650nm red at the same outputs. The flourescense really messes with your eyes - for example a blu-ray beam will seem as wide as a baseball bat after a few metres while the beam itself is actually still very thin.

I have made a small RGV spiro setup and a PHR at about 92mA matched a 5mW greenie pretty well.

Seb

 

[KGB_Productions]

Check this link out. It's a tool for calculating the chromatic coordinates of mixtures of monochromatic light and displaying them in a CIE xy chromaticity diagram.

This can tell you exactly how much of one wavelength will equal the brightness of another.

Index of /Chroma/distrib


Chroma - a laser color blender - Photonlexicon

 

[DJNY]

has anyone a burning graph to the different laser colours?

 

[ProjMan]

has anyone a burning graph to the different laser colours?

Not easily done. Cutting/ignition/'burning' power is a function of both laser wavelength and the reflectance of the target at that wavelength.