RGB laser, help please!!

[Stoney3K]

@Doc, I fully appreciate that adding some 532 into the 445nm might help alter the balance. After all you're effectively shifting the perceived wavelength upwards in much the same way that mixing red and green produces a wavelength thats perceived as yellow. I'd imagine adding a little green leakage into the 445 blue probably shifts it upwards to a preceived wavelength somewhere between 445 and 473 depending on the amount added.

You can always try to get the best of both worlds and invest in a small 473 to mix together with the 445. It won't be as expensive as a full-powered 473 or 457, but will push the perceived colour a little more out of the 'deep blue' range, while still keeping that colour in the palette.

50-100mW 473's aren't ridiculously expensive, they can also be installed later as an upgrade if you leave enough space.

The complete palette you get with 445-473-532-642-650 would probably give some striking colours.

[dnar]

I simply love these wavelength / power discussions!

Reminds me of the frequent "fans: suck or blow?" arguments of 10 years back in my extreme computer over-clocking forum days.

[p1t8ull]

You can always try to get the best of both worlds and invest in a small 473 to mix together with the 445.

The two people I know of that have used 473 and 445 together both said that the difference it made to the palette really wasn't as much as you would think and will most likely remove the 473 and stick with 445. Both used QM's with dedicated colour channels and being experienced guys would've set the palettes up, probably hundreds of times in one case, he's quite insane when it comes to colours, and alignment

That said you can't beat multi-line laser and a Machida grating for ooooooh effect IMHO

[Lasermad]

Having lived in a monochrome world for so long , as long as its colour its FANTASTIC to me .. a lot really is in interpretation , each persons eyes are so different.

( thanks to some amazing hard work and deals from simon and andyC my rainbow dreams will be reality soon ... Wooo hooo ... yeee haaa )

@DOC ... your photos there are frigging superb man ! kudos !

Paul

[buffo]

As for anyone else not favouring 445, I believe Adam (Buffo) has said he prefers 473. However, I couldn't tell you his reasons.

I can!

Quite simply, for a graphics-only projector, I prefer 473. Here's why: Most images we use have "sky" and "water" elements in them, and these elements look better when they're drawn in a light blue (ie: 473 nm) vs a dark blue-to-violet (ie: 445 nm).

If you're building a beam projector, by all means use 445 nm for blue, as you get the most bang for the buck. But if you're building a graphics projector, particularly one that will be lower power, then you should consider 473 nm for blue.

And to the people who say "just add a little 532 to the blue and you're fine", may I please direct you to the CIE color chart. Now, draw a line between 445 nm and 532 nm. And finally, check the color saturation at the point along that line that is closest to 473 nm (which is a nice light, or "sky" blue).

Many of you will be astonished to learn that it's less than 50%. (Around 45%, actually). And *that* is why a graphics projector with a 473 nm blue laser in it will look much better when rendering images that depend on that light blue color (such as sky and water effects). It doesn't matter how much green you mix in withyour 445 nm blue. It's always going to look unsaturated when compared to a laser that outputs at 473 nm.

And before anyone says "that's just theory, it's not that big of a deal in real life", let me remind everyone that I've organized over a dozen LEM's, so I have seen 445 nm projectors side-by-side with 473 nm projectors on *multiple* occasions, so I speak from experience. (In fact, it was Casey Stack who pointed out the numbers on the CIE color chart to me last summer, even though I had already noticed the difference in person way back when Aaron bought his 1 watt Kvant projector nearly 2 years ago.)

Granted, you can't create a deep blue-violet color with a 473 nm laser. But how many ILDA frames do you have in your collection that really *need* a deep violet? Violet is not a common color, but light blue is. From a robin's egg, to a drop of rain, to the blue eyes of your average blond cheerleader, light blue is the color you want, at least for graphics. And for a light blue, 473 nm wins - hands down.

As I mentioned before, beam shows are the exception. You don't really care about color balance for a beam show. You just want everything to be really bright. So it makes sense to use 445 nm blue in that case.

And yes, if you need to have a graphics projector that makes 4 watts of power, you're probably going to be forced to use 445 nm blue simply for cost reasons. But in a 500 mw projector, it's worth it in my opinion to spring for the 473 nm blue.

Adam

[absolom7691]

I know this thread is a couple months old but I would strongly agree with White-light. I have also seen 457nm blue and I think it looks great. As far as graphics go, 445nm is the worst choice for all of the above mentioned reasons. I can be made to have a decent beam, and the power certainly is there but there is no way to raise the aparent intesity. If you raise the brightness of the blue, you are just going to shift the color pallette and it won't look right. For price/performance, I would recommend 473nm before 457nm. For pure price, obviously 445nm. For perfect color and beam specs, 457nm.

I honestly wish I had the money for a 457nm. I am waiting for the diodes to hit the 450nm+ range (if ever). I think a nice 455nm~460nm would be perfect!

[Diachi]

My plan is to put 445 and a little splash of 457 into my RGB, then run the 445 a little 'hot' in order to shift the wavelength up a little bit. Going to have a little bit of 671 and hopefully a watt or so of 640 too.

Best of both worlds I say.

[absolom7691]

Sounds awesome. Fuller spectrum.

I have a 350mW 640 and a 200mW 532. My 473 is only 100mW. I am thinking of combining my 100mW 473 with about 100mW or more of 445. I think that will give me some nice blues and also bump the up the luminance a bit. With the 445 I have now, the power is there, but the bright blue is not.

[Diachi]

Yeah I'd say combine them. If you need the deep blues and awesome pinks and purples from the 445 you have them, but if you need the bright, crisp, blues of the 473 then you have them too.

[absolom7691]

What would be the best way to combine those, PBS or dichros? I imagine that I would have to get a specific dichro as I need it to be a very narrow band.