442 nm diodes...

I lack understanding on all sorts of things, but colour and wavelength perception is fairly basic. Judging the threshold into the wideband red part of the spectrum might not be, as it's clear that trying to go below 690 and driving it at tens of watts to match a 300 mW green DPSS would be daft. I'm just saying that when you're talking about wavelengths so far up the red band as to verge on orange, it's safe to say that most people do notice the difference. Everything I've said is purely to support that point, not to offend. I could take offense at the post whose logical inference is that I am a weird loser who can't get girls because I'm too anal about the nanometres, but what would be the point of that? I stand by my point about human sensitivity to colour. That is all.

Unless the two wavelengths are side by side, no one is going to notice the difference between 635 and 660, and perhaps if they do, i wonder how many people are really going to care at your typical rave laser show, or whatever.

Each wavelength has its pros/cons, but im afraid to say i really take to the sheer brightness 635 gives :) There has been talk over here about combining quite a few big red diodes to give a multi watt 635

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Originally Posted by dave

Unless the two wavelengths are side by side, no one is going to notice the difference between 635 and 660, and perhaps if they do, i wonder how many people are really going to care at your typical rave laser show, or whatever.

Each wavelength has its pros/cons, but im afraid to say i really take to the sheer brightness 635 gives :) There has been talk over here about combining quite a few big red diodes to give a multi watt 635

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Apart from the bit of the quote I bolded, I agree. If the thing is an aesthetic decision, I wouldn't have any argument at all, I'd agree. I already mentioned I think the contrast of the scarlet/vermillion of 635 with 532 is very cool. If I could afford lots, I'd have plenty. (Once built a digital clock with date in lime green, time in red/orange, it was the nicest digital display I ever had).

The bit I take issue with is this idea that there is no meaningful difference between 660 and 635. The logic of this is simple, whatever judgement is made on it: If one person cannot see it, they cannot be sure that others can't, so thay can't assert that the difference has no meaning. If a person CAN see it, as I can, as Marconi can, as that guy with the freezing orangey pointer on Usenet can, we can assert that there is a meaningful difference, but that some possibly cannot see it, or do not care. So if you can cater for those who can and do, you please more people. I always liked 650 as the optimum point, but that's just my choice of compromise. It's pretty much in the middle of the red band, and looks to me like a perfect red.

The thing a lot of people seem to be overlooking here is beam quality, 635/650/660 are straight diode lasers, 671 is DPSS, there is a notable difference in beam quality, and 671 is available in reasonably high power levels, I would say up to 1W is not out of reach. Also most people here are mixing the red with two other DPSS lasers, so having the red dpss keeps the beam characteristics in line with the other colors for good long range mixes (comparable diverenge/size/etc), these things can be corrected with aspheric optics and beam expanders/collimators, but to me its just easier to avoid the losses and keep the starting beams as close as possible. The color gamut is very noticable. Forget about deep reds for a second, try and make that deep purple/violet that everyone loves with a 635 (wanna do it real nice you need 671 + 457). In my opinion the main advantage of a laser show display is color saturation, if you have limited range (ie long wave blue, shorter wave reds, etc), you are not doing a whole lot better than a good wide color gamut video projector with a xenon/halide source as it can make those wavelengths too. To see available color gamut, what you need to do is take a look at a CIE chromacity curve diagram, make 3 points on it (one for each wavelength), connect the dots, it will form a triangle, and inside the triangle it will show all the colors you can possibly make with those 3 wavelengths.
-illuzion

Ummm... Yea... How'd we go from 442nm blue to an argument on red? :confused: Personally I want the ability to get as many colors as I can, so the wider the difference between my highest and lowest wavelenth the better IMO. But it is also right, when I was going to raves to go to raves, I didn't give a shitte what range of colors the lasers could do, just as long as the lights kept moving... :cool:

Sorry David, I knew someone had posted that picture; thanks for the correction. :D

and thanks dave... the Pangolin color setup and usage confuses me a lil... but I'm gettin there. :)

Back on topic... I want some deep blue like that in my projector... :rolleyes: ;)

OK, here is a though:


Take 650nm and a 635nm diode of the same power. Mix green with the 650nm beam so the final color matches the 635nm color.

Which beam will be brighter, the 650+green or the 635 only beam?

We ran a lasershow just recently buffo where our new 400mw 635nm laser projector was physically strapped ontop of our RGB (which uses aroudn 600mw of 650-660nm).

To be honest, there was barely any noticeable difference between the 635nm and 650nm... i mean, yeah, the 635nm was not as deep as the 660nm, but i had to look REALLY hard to notice. The only difference between the two, was that the 635nm was fuck loads brighter, and about twice as divergent ;)

Edit: I'll also just add, the average non-laser type person would NOT notice the difference betweent he two if they were NOT side by side....

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We ran a lasershow just recently buffo where our new 400mw 635nm laser projector was physically strapped ontop of our RGB (which uses aroudn 600mw of 650-660nm).

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Hey Aijii;

Huh? How'd my name get in there? (bold emphasis added) This is my first post in this thread.?.

Granted, it's been an interesting thread, and it has made me re-think my own thoughts on color perception, but I purposfully stayed out of the discussion on this one.

Perhaps you were replying to Zoof?

Adam

I dare to say that I see everyone's point in this discussion. The reality of it seems to be that if you're doing commercial lasershows it really isn't about nanometers but about revenues, thus investments and return. So the real question isn't brightness v.s deepness but about making some $$

But when it comes to laser-freaks I guess it really the same as audio-freaks who can endlessly discuss what amplifier, cd player, pre-amp, speakers and other parameters create the best music. When I bought my audio set I simply abstracted from all that into one boolean: good or bad. I bought 'good' and I'm still very happy with it :)

On the other hand , when funds and time permit, I want to have a laser projector with all possible laser lines and count nanometers every once in a while just to see what colors can be created, how deep, awsome and bright. In my free time I discuss this on the internet with like-minded people and really enjoy that. And that is exactly what makes everyone unique and interesting.

Now back on topic:
For some reason I'm more attracted to 442nm than 635nm, probably because I have 650, which is a very nice red and I feel that my 473 has a bit of a wash-out effect and wouldn't want that for red. So I'm on the deepness side of this discussion but then again the powerlevels I play with are low.

I played with the idea of getting into commercial laser shows, probably won't do it, but if I did I would have to invest in high power gear and then I would stand by the very first part of this post.

jm2p

I also dont mean to offend anyone, just my preference.

Altho I dont provide lasershows, so making money from that is not too much of a concern for me.. but I do like seeing them and I do notice what they are using.
I've be going to lasershows since the 70's , Id say probably at least 50 of them and from the BIG BOYS, I especially like the planetarium style ones where i can relax and see everything. I look at quality and I'm there to have fun. And yes, Bright is they way to go if you want to be seen.....outdoors especially.
But if I was to do shows, I would want the best I could scrounge up to look better (and that means more cash flow) than the guy down the street or that last show I seen last saturday where they looked bland.

At home, I like seeing all the different colors my system can make, Thats why I went with analog modulation to get all that that is possible..out of it.. colors ! and more colors !
Not something I can see on TV or a rave. I want something different that is not run of the mill.

Not that I dont like 635, I have a 600mW that I like a lot, but the diodes are still too expensive and still have terrible divergence. to me.
I am still looking for these diodes for those that want them , as I do..But to make them cheap is another story.
Too cheap and you have garbage.

I to am also looking at 442 or even 457nm blue...and at about 400mW would do it nicely...very pretty.
Really extend the color pallet some more.!!!

What would you rather have, something run of the mill?
Or something outstanding that not many others have seen before..?

Its like the difference between a McIntosh or a fake Sony ES

Thats my point.

Thanks Zoof for showing the 442 diode..I will be looking hard at that.