Power compared to Brightness

[instinct]

I have been trying to find information regarding power to brightness. I remember reading you need about 4 times that amount of power for a laser to "appear" twice as bright. Can anyone confirm this? So, If I had a 100mw laser, I would need 400mw if I wanted it to look twice as bright? I realize that not everyone sees brightness in the same way, I just wanted to get a general idea.

[gottaluvlasers]

that was always my understanding ESPECIALLY with lasers. Lasers inherently are so bright already, the eyes get saturated at even lower powers.

i had a physiscs prof in college explain that theory to me. (4X power=2X bright). however, as you stated, it is not an exact science.

-Marc

[Xytrell]

Unless they're side by side, you may not even notice a difference for the reason stated above, and the fact that our eyes adjust to brightness (via pupil size and desensitizing of the retina) which is why we can operate just as well in a comparably dimly lit room and in direct sunlight.

[badger1666]

yep this all sounds about right,
i have seen a 1w kvant and 3w kvant side by side at a uklem,
could not tell the difference, this is in your average club venue
the only time it pays to have more power is when it comes to larger outdoor shows, then you need lots

[sbk]

yep this all sounds about right,
i have seen a 1w kvant and 3w kvant side by side at a uklem,
could not tell the difference, this is in your average club venue

What you try to tell is that I just spent some crazy money to replace my 300mW 532 and 200mW 473 by 1W 532 and 1W 445, for not to see the smallest difference????

[instinct]

Another n00b question. What about blue vs green? About how much more power do you need for the blue to look as bright as a green.

[badger1666]

thats a big power jump yes you will see the diference as it goes 4x the power for 2x brightness, but for club use you would be better to buy another projector and improve the display that how i would do it

[colouredmirrorball]

I was once at a party organised by my school so I could come earlier and help with setting the stage up/trying to get a job in the local light store. I asked what the power was on the lasers they used and the answer was "40 mW on each". I tought there was no way those thingies could have a big effect in a 1000+ venue but they were surprisingly bright enough. Not the best show but the crowd didn't care. The operator turned down all the other lighting for a few seconds so the lasers had at least a bit of an effect. More power just means more chance on eye injury...

In january I'm organising a party and I plan on hiring two 2 W RGY's (gas) and an 8 W Argon from a friend... See if we need to turn the other lighting down too.
>B-D

[FourDee]

gas <-> RGY ????

[colouredmirrorball]

That's what he said.
Or that's what I misunderstood.