how 520nm brightness vs 532nm in an RGB buld

[markmtts]

Look up the response of the eye...peaks around 555 nm so 520 nm will appear less bright for sure. A good DPSS crystal laser will have supperior beam quality to any mumtimode diode or it should anyway. The diodes should modualte better and be way more reliable IF NOT OVERDRIVEN! Phil

Just a question regarding the apparent brightness of 532 vs 520 - that the peak around 555nm is in daylight where as isn't it nearer 505-510nm at night / in the dark ? I was wondering if therefore (in theory) - in the dark the 520nm green would appear to be 'brighter' or more defined or am I missing something here ?

[edison]

In the dark any lightsource (laser or not) is looking brighter then in broad day light. Since 532nm is close to the "eyepeak" of 555nm , the 532nm is always brighter the 520nm. But since most green 532nm have poor modulation and are not heat and cool drivers and compare it with the 520nm that has the exact same power but perfect modulation (assume the driver is designed perfectly) then the 520nm wins. You still missing the bright yellow line though. A DPSS is still the way to go because of the better beamquallity but with a good driver.


Viasho recently launched their new OEM module and that comes with a Heat and Cool driver. CNI OEM-F has also heat and cool on request. Laserwave is stuburn and are convinced that they can go without........ We asked many times (begged) do a heat and cool driver but in the end of the day its their choice. Viasho went with a Vacuumcleaner on top of their modules with the size of an 1995 mobile phone while laserwave and CNI went with a different construction so no fan is needed and is allot smaller in size. Viasho disappeared from the market for a while but i think he will be back soon.

He made a very good move by going OEM-F /laserwave style with Heat and cool. If the beam is less then 1mrd in divergence with a 4-5mm beam as standard we have a nice green that,s for sure. Many people have already projectors with 532nm in it so they will stick with that so they can mix and match.

[sbk]

Just a question regarding the apparent brightness of 532 vs 520 - that the peak around 555nm is in daylight where as isn't it nearer 505-510nm at night / in the dark ? I was wondering if therefore (in theory) - in the dark the 520nm green would appear to be 'brighter' or more defined or am I missing something here ?

I have always wondered if the vision of peoples watching a laser show is photopic or mesopic (scotopic not for sure). If mesopic, certainly the 520nm line will appear equal or even brighter than the 532nm line!

[steve-o]

Hmmm ..
This has been covered before, but .. interesting ..


From this:
http://webvision.med.utah.edu/book/p...ics-of-vision/

[planters]

I think the chemistry of the rods and cones will not shift and when looking straight at the light I believe the photopic curve will dominate.