Brightness

[lasermanXYZ]

i have never seen a 1W, 1.5W or 2W blue laser at night in real, but do u notice a considerably difference in beam&spot or is it negligible at this high outputs?

 

[Zeebit]

The perception of brightness may vary from each individual to the other. Personally, I don't see much difference between 445nm diode driven at 1A and 1.8A which roughly translates to 1W and >=1.5W.

 

[Livinloud]

I have owned a 1.5W, 2.6W and 3.2W 445nm and had them on at the same time. There is very little difference in brightness or burning power.

 

[NO4H99]

If you put them next to each other, the difference is noticeable. Not huge though.

 

[Shakenawake]

For my eyes, 3.3W looks nearly twice as bright as 1.5W of 445nm, never owned one in between these powers, but 1W is really hard to distinguish from 1.5W, though I disagree with livinloud about burning power, 3.3W is much more strong than 1.5W. Ignition of objects is cake with 3W, but requires more time, a steady hand and a focal point to ignite with 1.5W. needless to say, all these need extreme caution to be exercised.

the dots will only be different with different diodes and lenses, but will all be multi mode with more or less rectangle shaped dots

 

[djQUAN]

When I powered the 9mm at about 3W output, put my 1.7W beside it and the brightness is noticeable but only side by side. It was daytime though so the effect may not be as dramatic at night.

 

[Tmack]

I have a 1.4w, 2.4w, 3.5w and they do have a noticeable difference, but I see it more in the reflected light. The 3.5w will illuminate the entire area with the reflected light it produces. The 1.4w still lights the area but not as bright. I do agree, they do have to be side by side to get a sense of the difference . And my 1.4w burns very fast, but not at the distance that the 3.5w can burn. And the 3.5w doesn't need to be focused as accurately. Get close to focused and it's been on fire.....

 

[cheech226]

I found the difference very noticeable between a 1W and a 3W 445. the 3W being roughly twice as bright.

 

[Livinloud]

Every eye is different. No one can answer this question. As far as burning if you have a 1.5W focused perfectly it will burn as quick as a 3W focused the same. I guess it also might depend on what you are burning but I did it with newspaper balls in a campfire

 

[Atomicrox]

I have a 1.3W and a 3W, the brightness difference is only noticeable comparing side by side. It doesn't make much difference when looking at the beam from the back, but it makes a lot of difference when looking sideways.

It does make a lot of difference in burning power, though. 3W can "pop" wall paint, plants and a lot of not-completely-flamable stuff, which doesn't happen often with 1.3W. It also has a tendency to set fire instead of just cutting/scorching flamable materials.

 

[DTR]

Wavelength also is a big factor. If you have a 3.5W diode that is for sure a freakishly efficient diode and is probably running at a much lower than average wavelength due to the fact the diode is not dissipating as much energy as heat. Then if you have a diode that is only giving 1.5W that is a low efficiency diode which is very possible as someone maybe was hoping for a 2W and it ended up freakishly inefficient then it most likely will have much higher than average wavelength making the two lasers not that distant in terms of visible brightness. This is one of the reasons I don't stress to much on having a super efficient diode unless you just like seeing a higher number on an LPM.


This tool is not perfect but it does illustrate some extreme examples.
Beam
Beam: (450nm 1500mw) vs. (440nm 3000mw)
Dot
Dot: (450nm 1500mw) vs. (440nm 3000mw)


It gets more interesting in this comparison with only a +/- 3nm spread if you compare a lower efficiency 9mm that is only giving say 2.4W @ 2.4A and has a higher than normal wavelength to a 9mm that is 3.2W @ 2.4A that is giving a lower than average wavelength.
Beam
Beam: (448nm 2400mw) vs. (442nm 3200mw)
Dot
Dot: (448nm 2400mw) vs. (442nm 3200mw)

So in the end you can't really do a meaningful comparison on lasers unless you know the wavelength they are running as well as the output power.:beer:

 

[Atomicrox]

For the record the 3W I mentioned earlier metered around 454nm, while the 1.3W metered on the low 440nm's. The measurements were made with a "wall spectroscope", not with a proper spectrometer. Those lasers also have a very clear color difference. Even non laser people say one is blue and the other one is slightly purple.

 

[lightinggeek]

You can only talk about brightness comparison at same wavelength level. I have 450nm show lasers ranging from 500mW to 3Watt. I can tell the difference (put laser side by side) if power difference is >500mW.

 

[Pi R Squared]

I also notice a difference in brightness and a big difference in burning ability. If one laser is twice the power of the other one I think you would notice a difference.

Alan