>500mw 635nm vs 1.5W 445nm - Brightness comparison?

[reginak]

I'm ready to buy a CNI PL-C 635nm >500mw, I know the beam is thick, squared with a big divergence, but everyone tells me that this laser is bright with a bright beam, so its what I want right now. (building a collection of the brightest possible handhelds)

My question is simple, how the brightness of this laser will compare with a 1.5W 445nm? Will the same brighness? Same beam visibility? Or more? Or even less?

Thanks!

 

[DJNY]

I´m quite sure that it is going to be less visible than 1.5W of 445nm.

Aryntha is the best source for this question!

 

[RA_pierce]

Both 635nm and 445nm are pretty low on the scale of visibility, albeit closer to the peak than 405nm and 655nm.

Because 445nm is attenuated by particulate in the air and the air itself (Rayleigh scattering) the beam will be more visible.
Assuming equal power, the two wavelengths might be pretty close in terms of "spot" brightness. I would wager that the 1.5W 445nm would be brighter simply because it's nearly 3X the power.

One advantage longer wavelengths have, though, is that the eye can focus on them better. I've noticed that even with tons of power, 445nm, like 405nm, the beam becomes "washed out" over a significant distance. This is because our eye's lens focuses short wavelength light just above the retina, making the image appear blurry. In daytime, 405nm and 445nm even in high powers is difficult to spot.

In contrast, 300mW of 655nm, which is much less bright than ~1W of 445nm up close, can easily be spotted outdoors in sunlight for at least 100 meters.

Maybe Aryntha will stop by and tell us what he thinks. As far as I am aware, he is the only one on the forums with a high power 635nm portable (Laserglow Orion HV).

 

[reginak]

Thank you DNJY and RA_pierce, you are good reference because both have many wavelenghts, much easier to compare.

RA_pierce wrote:
In contrast, 300mW of 655nm... ... can easily be spotted outdoors in sunlight for at least 100 meters.

Yeah, I saw this at aryntha Orion HV topic, it was a really bright spot outdoors in sunlight.

I only hope my 532nm >600mw Jetlasers arrives at my house until this friday.

Thanks again guys! Hope aryntha stops by too.