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# G3 Lens??? Anyone Know What That Is?

#### Encap

##### Well-known member
I have a 300mW green laser and from the pictires ive seen of 4W 465nm lasers it looks WAYYY brighter than what I have. Are we talking about the beam or dot? And ok how is that picture relevant to what we are talking about? Thats 30mw of 488nm....ill have 4,000mw of 465nm.

HPO OK here are some relatively accurate, but not absolute, insights for you to consider:

The beam of a 4000mW 465nm is 1.93 times brighter than the beam of a 300mW 532nm ---the dot of a 4000mW 465nm is 1.11 times bright than the dot of a 300mW 532nm laser.

A 500mw 532mn green dot is 1.7 times brighter than a 3500mW 465nm dot and approx 1.5 times brighter than a 4000mW 465nm dot,
A 500mW 532nm beam is approx the same brghtness as a 3500mW 465nm - yes - 4000mW 465nm beam is 1.16 times brighter than a 500mW 532nm beam.

Brightness is human visual perception by a "normal" human eye--Nothing hypothetical, imagined, imaginary-- nothing to do with camera images of any kind.

Human visual perception is a very complicated thing/topic/subject.

Comparing perceived brightness of a single wavelength the inverse-square law applies when talking about beam brightness, so 4x the power = 2x as bright.--so 3.5W of 465nm is 1.58 times as bright as 1.4W of 465nm as follows:

Percent brightness increase ≈ √(P2/P1)×100

In case of 3500mW vs 1400mW of 465nm ---3.5/1.4 = 2.5, √2.5 = 1.5811 X 100 = 158.11% brighter. 4000mw is twice as bright as 1000mW for reference.
Let's assume the laser you receive is a 4000mW, 465nm and not a 3500mW --the beam of a 4000mW is 1.69 times the perceived brightness of a 1400mW.

The beam of a 4000mW is 1.069 times brighter than that of a a 3500mW 465nm

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#### HighPowerObsession

##### New member
Haha damn well looks like you certainly have done your research. Ill definitely be keeping ths thread to resort back i the future. But bottom line, a 4W 465nm laser beam is going to be super bright. And yes it will be 4W; I have been speaking to Gray alot and he promised me a 4W 465nm.

#### GSS

##### Well-known member
Haha damn well looks like you certainly have done your research. Ill definitely be keeping ths thread to resort back i the future. But bottom line, a 4W 465nm laser beam is going to be super bright. And yes it will be 4W; I have been speaking to Gray alot and he promised me a 4W 465nm.
He sure did
For what its worth, I have no problem seeing my 1W 445 in ok lit room.

#### HighPowerObsession

##### New member
Thats awesome, I cant wait to see mine in the night sky.

#### Koff

##### New member
Imo it's going to be ALOT brighter than 500mw 532nm. People still trust the "Relative Perceived
Brightness Calculator" ? It's not even correct. It claims my 140mw 520nm dot is 1.8x brighter than my 1300mw 445nm dot. I checked and the 520nm is not even brighter lol. The 445nm is little brighter.

It also claims the dot of 1000mw 532nm is as bright as 18909mw 450mw dot. Lol

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#### Encap

##### Well-known member
Thats awesome, I cant wait to see mine in the night sky.
It is going to be a great laser for sure--everything JetLasers makes is best professional level high quality product made by people who care about and love what they do. JetLasers was founded by laser enthusiast engineers not people who would be selling ping pong balls if they were not selling lasers.

Good luck with it---use it safely and employ proper safety practices. A 4W 465nm laser is a very dangerous laser for several reasons--it can cause permanent occular damge as in complete blindness forever in less time than the human blink reflex of 0.25 secounds. So fast that there is no possibility of making a correction and avoiding an "accident" once it has initiated. See what happened to an experienced and careful LPF member while using a 1W 445nm laser here: http://laserpointerforums.com/f53/hit-eye-1000mw-445nm-blue-laser-69469.html Also have a look/read here: http://laserpointerforums.com/f53/irreversible-vision-damage-don-t-turn-blind-eye-laser-hazards-71299.html

PS When you start talking about "subjective" brightness values (i.e. - looks brighter), you need to take eye's brightness response curve into account--human eye has a logarithmic rather than linear response to light is the point. It is your eyes response and brain that perceive a beam's brightness based upon sensitivities to the different wavelengths/different energies reflected back to your eyes by particles in the atmosphere which reflect or scatter different wavelengths and energies at different rates depending upon sizes and number of particles or molecules present.

A 1W 532nm green and a 7W 465nm blue have the same brightness beam in a vacuum--- zero brightness/no brightness--there is no beam in a vacuum, however, under the same atmospheric conditions they have approx. the same brightness beam.

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#### Atomicrox

##### Well-known member
Percent brightness increase ≈ √(P2/P1)×100
Do you have a proper, scientific, reference for that formula?

#### dden4012

##### New member
The NUBM07 465nm Laser Diode isnt going to be tamed by a 3 element lens. Search the forum for this diode and read what our elite laserists have gone through for managing this diode. I am surely not going that far with it. As far as the length yikes! Maybe you could use 2 18350's idk. Cant wait for your review!

#### HighPowerObsession

##### New member
Yeah Ill be using 2 X 26350s unless by some long shot the I find 14" to not be that long. Im going to have a 14" laser no matter what if I ever plan on using the BE so whatever, Im kinda over talking about the length. And is there a better lens to "tame" the 4W 465nn doide? Please let me know because I have already tried looking at other lens and its a frickin nightmare....hundreds apon hundreds of lens listed from the top to the bottom of the page for 10+ pages straight. I spoke with someone from the website and they said I could even combine lens together so yeah as far as Im concerned Im sticking with the 3-element unless someone here can recommend a better divergene tested lens.

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#### HighPowerObsession

##### New member
Oh and as far as the brightnes goes, I literally couldnt care less how bright the dot is; I already know its going to be ridiculously, uncomfortably bright. All I care about is how bright the beam is and I want there to be the best possible divergence. Btw this laser wont be my primary burner; I have already picked out an INSANE 405nm laser that im gunna buy for everything burning.

Idk if you guys have seen this video but I just found out that Sanwu sells a laser very similar to this one but the laser they sell has 2X the power that the laser in this video has. Btw the divergence is 0.4mrad....you guys probably already knew this but im still amazed by this.