blue VS green

[caleb]

how many mw's in green would you need to equal the beam visibiliy of a 1mw blue?

 

[VillageIdiot]

About 0.15 mW... blue is a lot less visible you know.

 

[tomcat]

well there will be no beam visibility as suck but for brightness of the spot blue (473nm) to green (532nm)

if we say 532nm is about 0.9 on the brighness scale and 473nm is about 0.3 so 1mw of blue would be equliv to about 0.33mw 532nm

at higher brightness levels blue looks more bright compared to green on relative scales at night because the human eye at night is more towards 500nm not 550nm in daylight

 

[el-taco]

Not to mention green is pretty much the middle of the spectrum and the fact that blue is almost at the edge of the (visible) spectrum...

 

[caleb]

hmm, so why use blue in astronomy for...

but a more insanely un-answerable question is why make the max power of laser inports into Aus <1mw??? woah, trippy man...

 

[VillageIdiot]

well there will be no beam visibility as suck but for brightness of the spot blue (473nm) to green (532nm)

if we say 532nm is about 0.9 on the brighness scale and 473nm is about 0.3 so 1mw of blue would be equliv to about 0.33mw 532nm

Look at the graph again and tell me that 473nm is 0.3. :\ Unless you have a better graph, 473nm is 0.1. Works out to something like 0.11mW (so my original figure was a bit much)


And I've never heard of blue lasers being used for astronomy. Seems a bit silly to me....

 

[brtaman]

This one was posted originally by GamerBR, I believe.

Actually the difference in beam visibility between green and blue isn't as dramatic as most graphs show. In the dark I believe that they are almost equal as far as beam visibility goes. I'd say 1.2-1.5mw 473nm=1 mw green, atleast at the power level of a RPL 35 vs. DX "true" 50. I was a bit iffy about getting the blue rpl after seeing all the graphs, in which 473 is about equal to red, but went ahead and bought it and was very pleasantly surprised.

The beam comes out a beautiful blue and doesn't get drowned out by a DL-95 or DX laser shinning next to it. I believe the graph I have posted to be a very accurate representation of how visible the lasers are from a beam point of view. I almost never use my laser in the daylight so I can't compare there.

However, the dot is another mater, the greens dot is visible at far away distances while the blues gets drowned in the environment, but this is due to the scattering effect at different wavelengths, I believe.


Thanks
brtaman

 

[Cyparagon]

0.104 and 0.88496 are the photopic luminous efficiencies of 473nm and 532nm respectively.

 

[Ace82]

The blue RPL 35 can be used for star pointing...
But it's about equal to 10mW (max) green, as it is definatly brighter then one of my DX 5milaWatters

click "sold" in my sig and you will see some beam shots of my 532 225 and the 473 35 and beam shots outside even in twilight.

And even though our eyes adapt to the night, I think green still stands out more then blue.

 

[randomlugia]

I agree; I think green is definately brighter all the time.

 

[darklandz]

i remeber comparing my RPL blue 44mw vs a dx 20mw green, in the dark with a bit of cigarette smoke.
the blue beam totally drowned the 20mw green laser. maybe the dx green was only throwing out 12-15mw but i remember the blue totally dominated.
best way to tell would be to have both a green and blue at the exact same output.

 

[Chicxulub]

When my Aquarius is running at it's absolute best, 17mw, it's about the same as my 5mw Lyra in the light, and noticeably brighter than the Lyra in the dark.

Take from that what you will.