Balanced RGB?

[drezglis]

Hi all, I have a question?? What sort of ratio does it take to make a balanced system with Red, Blue, Green? And if I wanted to use other nm like 405nm in place of 445nm of each region in nm for each color what are the properties to make a balanced light show? Example if 445 nm is 1.7 W what would the properties of the other 2 colors have to be in order to create balance? And how does lens spread rate (focal properties?) effect this. As well as how does each nm of visual spectrum effect this as well? So there most be some kind of formula can anyone point me in the right direction?

[Bradfo69]

You're going to end up with about as many answers as there are members. There was a program, I think called, Chroma or something like that, that people used to talk about and even then there would be heated debates about the results.

Honestly your ratios are going to be different for all types of wavelength combinations so, it's a difficult question to answer. Plus there are software adjustments that can be made to tweak it even more. And even the quality of the optics affects it to a degree based on losses.

In my particular case, I have a projector (built by CT Lasers) that we really scored on, as it's got one of the most amazing arctic whites you'll ever see. And a LOT of people have confirmed and agreed with that. I do think luck plays a big part of it but.... (and this is advertized - not exact) 1.2 w of 640, 900mW of 445, and 800mW of 532. So, close to 1:1:1 for THOSE wavelengths. Change it to 638, 650, 635, 637, 405, whatever, and that all sort of goes out the window.

[Bradfo69]

Revisiting this, I'm also not certain you can get a "balanced" white using 405 in the first place. It's not really blue - it's violet. I know they're out there but, I don't recall seeing the output of an actual RGV projector and what the "white" looks like.

[james]

That depends a lot on how you use it! If you plan to use it to project graphics on a screen, that screen might be paper or cloth with a whitening agent. That will floresce as blue when the 405 hits it. It actually works pretty well.

But since 445nM diodes are really cheap these days, there is not much point in not using them.

[buffo]

If you are using 637 nm for red and 445 for blue, a good starting point is a 1:1:1 ratio for Red:Green:Blue

If you are using 650 nm for red and 445 for blue, a good starting point is 2:1:1.

As Brad said, color balance is subjective, so you're going to get different answers from different people. In the end, what looks good to you is what works.

Adam

[andy_con]

Chroma - fight fight fight

[White-Light]

Chroma - fight fight fight

[LEDpaint]

Much of this also depends on your application: beamshows and abstract graphics for raves and clubs, or high end graphics for corporate shows.

If money is no object, get super tight Coherent OPSL with nice, tight beams. If money is limited, then you'll be getting modules with differently sized beams at each apperture, different divergences (your "lens spread"), and different spot shapes that will never, never, never overlap perfectly. If you can merely get close to the magic 1:1:1 at 637-640 red, you're fine. Mine's a nice white at 1:1:1.5 with a 640 red, but I've seen ok white with less power in the red.

Will anyone notice you don't have a snowy bleached white for beamshows? No, they're too hypnotized by the awesomeness of laser light. For graphics shows, maybe, depending on how divergent the individual beams are and whether you're doing animated characters, text, or just doing trippy abstracts. Just try to get them as close as you can in divergence (smaller=better) and beam size at aperature and you'll likely be fine.

[Dr Laser]

Depends what white temperature you want to get. 8k or 4k. For 4k you will need more red. for 8k you will not need much. For R 635/G 532/B 473 you need 2-1-1 for 445 you need 1.5 for 650 you need 4x. I'm a 4k guy.

[laserLips]

Can anyone tell me the best ratio for R(637) G(532) B(445) please