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dreamsfain

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Hello

I always wanted to play with lasers and now my dream is coming true. So I will ask all the possible question about lasers that I can think of before I buy my first laser.

The first question will be about the danger of an unfocused 4W laser at around 5 meters distance
 





dreamsfain said:
Hello

I always wanted to play with lasers and now my dream is coming true. So I will ask all the possible question about lasers that I can think of before I buy my first laser.

The first question will be about the danger of an unfocused 4W laser at around 5 meters distance
Click to expand...


Your question isn't specific enough - unfocused tells us nothing. 5 meters doesn't tell us much either. Direct exposure? Reflection? How much is it "unfocused", i.e. what's the beam diameter? What are you trying to achieve?
 
Thank you for helping me to clarify my question, the diameter will be 20cm and direct exposure
 
Sounds to me that someone is trying to make a dazzler in which case. NO. Don't do it. Both of your threads mention a 4 watt laser unfocused and direct eye exposure.
4 watts as a first laser is also completely ridiculous no matter the person.
At those kinds of powers, you even have to worry about accidentally setting stuff like curtains on fire.
My old ~1.2 watt 445nm would char walls from a few feet away if sat down.
Imagine what that would do to a pair of eyes.
5mW's was determined to be the most power that could be safely used such that a person's blink reflex would save their eyes from permanent damage.
Yes their are ways to make the exposure safe but it any variable changes it can quickly become damaging. For instance if the focus changes or the distance changes or even if the power density calculations were done improperly or using incorrect measurements.
If you are wanting something bright but defocused, look into LED's. some of them still pack a serious punch but aren't coherent and don't as easily cause stuff like retinal burns from a distance although even those can cause damage under the wrong circumstances.
 
Thank you for your answers, the room is 5 meters long and I wanted to know if that kind of power is dangerous even if its not focused, in case I would look at the laser by accident
 
dreamsfain said:
Thank you for your answers, the room is 5 meters long and I wanted to know if that kind of power is dangerous even if its not focused, in case I would look at the laser by accident
Click to expand...


Anything >5mW is considered potentially dangerous for direct exposure.

And to qualify that, <5mW is also potentially dangerous, but your blink reflex will generally save you in the event of an accident.
 
I am very curios to try to zap mosquitoes with the laser even if it isn't focused. Could the laser damage their wings at a distance?
 
Get yourself a good Host, like the one below, to put your 4w Blue laser in.
Then you can zap those pesky Mozzies safely.

See this thread: Hit in eye with 1000mw 445nm blue laser

Raid.jpg
 
If the power would be dissipated equally over the surface then it would be 10mw per square cm
 
The "Hit in eye with 1000mw 445nm blue laser" was 60cm from the laser so for a 4w laser it would be very dangerous at 2.4 meters for my eyes don't know how this will work on mosquitoes

Has any one build a bug zapper with lasers?
 
dreamsfain said:
The "Hit in eye with 1000mw 445nm blue laser" was 60cm from the laser so for a 4w laser it would be very dangerous at 2.4 meters for my eyes don't know how this will work on mosquitoes

Has any one build a bug zapper with lasers?
Click to expand...

You should build a bug zapper with electricity or poison.
No other method is efficient. Lasers introduce risks to yourself and to others.
 
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