FNinjaP90
Enlightened
- Joined
- Jan 8, 2003
- Messages
- 888
A while ago I remember asking how many lumens lasers puts out. Someone told me that a laser can't be "assigned" a lumen rating. If any of you guys aren't familiar with lumens, it's what the rest of this forum will give an arm or leg to get more of in their flashlights. A small 2xCR123 light will give around 60 lumens, and a big spotlight will give around 1000 lumens.
According to wikipedia, ideal 555nm light will give 683lm/W. This is the highest luminous efficacy possible for light, since the human eye is most sensitive to 555nm light. For example, incandescents give around 20lm/W, LEDs around 30lm/W, and HID's 100lm/W. Looking at the graph of photopic vision:
A 532nm laser has a luminosity function of .89, and the other, "dimmer" colors have their respective luminosity functions.
What does this mean?
For example, 100mW of pure 532nm light will have (683lm/W)(0.1W)(.89)=61 lumens. That's the same brightness of a Surefire E2e flashlight! And I thought that lasers were dim.
A 200mW 635nm laser will only put out (683lm/W)(0.2W)(.24)=33 lumens, or appear half as bright as a green laser of half the power output. 473nm blue is even dimmer, and the near-IR 670nm red is very very dim.
According to wikipedia, ideal 555nm light will give 683lm/W. This is the highest luminous efficacy possible for light, since the human eye is most sensitive to 555nm light. For example, incandescents give around 20lm/W, LEDs around 30lm/W, and HID's 100lm/W. Looking at the graph of photopic vision:
A 532nm laser has a luminosity function of .89, and the other, "dimmer" colors have their respective luminosity functions.
What does this mean?
For example, 100mW of pure 532nm light will have (683lm/W)(0.1W)(.89)=61 lumens. That's the same brightness of a Surefire E2e flashlight! And I thought that lasers were dim.
A 200mW 635nm laser will only put out (683lm/W)(0.2W)(.24)=33 lumens, or appear half as bright as a green laser of half the power output. 473nm blue is even dimmer, and the near-IR 670nm red is very very dim.
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