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