635 vs. 660 vs. 671??

[gottaluvlasers]

does anyone have or have an idea where i can see a REAL WORLD comparison of 635 660 and 671 red IN ACTION?? both a display (animation or graphic or something. AND a beam shot??

i am really trying to decide whether spending the extra $$ for DPSS red is worth it. i know, superior beam quality. but its also much "dimmer" therefore more power and in the end more $$

anyone got pics and or preferably video??

thanks!

Marc

[allthatwhichis]

If you check out the FLEM 1.5 thread there are some pics of 635 vs 658.

[buffo]

I don't know anyone with a 671 nm DPSS red. I've seen the 635 vs 660 comparison first hand however (TWICE, in fact!), and I can affirm that 635 nm red appears 5 times as bright to the human eye as 660 nm does. I'm pretty sure 671 nm will end up being about 7 times dimmer than 635...

My personal opinion on 671 nm is that it's just too far down on the spectrum to be viable, unless you don't mind spending as much on your red laser as you do on your blue one!

660 red looks great, but truthfully to the untrained eye 635 nm looks just as good. Sure, side-by-side tests make it easy to see which is which, but if you just walk up on a projector that is playing a show, it's hard to tell which red it's using.

If the 635 nm reds had the same beam specs that Marconi's Maxyz modules had, I would go with 635 red from now on. But all the 635 diodes I've seen have beam specs that look like crap. I'm sticking with the Maxyz modules for now, both because of the superior beam quality and the affordability of them.

That's not to say that I wouldn't like to have a 671 nm red... If I win the lottery I'll probably buy one. (Of course, in order to win the lottery I'd have to actually buy a ticket... Lottery is a tax for people who are bad at math!) If you've got the cash, and especially if you're building a multi-watt whitelight projector, then 671 is without a doubt the cat's meow. They're just too expensive for the average hobbyist, in my opinion.

Adam

[gottaluvlasers]

thanks adam!! thanks allthatwhich is!!

one day, gotta buy you 2 a beer! (or 2, or 3, 0r 4....hehehe...)

ok, CNI 50mW 635 (just say for simple maths sake, $100) vs. Maxyz 50mW 635 (again, simple math- $100) and it was YOUR $$...which one?? this is a club install. so it WILL be used quite often!!
whatcha think?

[carmangary]

I can affirm that 635 nm red appears 5 times as bright to the human eye as 660 nm does.

How did you come to this conclusion? I mean, why 5 times as opposed to 3 times or 6 times brighter?

[allthatwhichis]

At SELEM we did a side by side and at FLEM 1.5 we did a little more in depth side by side using a lasercheck each time. I think Adam's 2 maxyz at 360 or so after the galvos and David's 635 lasever running at 75 or so mW. 75*5=375...

[carmangary]

Oh I see. That makes sense. Thanks.

[The_Doctor]

660 red looks great, but truthfully to the untrained eye 635 nm looks just as good. Sure, side-by-side tests make it easy to see which is which, but if you just walk up on a projector that is playing a show, it's hard to tell which red it's using.

I've seen that said several times, and each time by people who have seen lasers first hand, but I still don't agree with it. While some can see it that way, the fact remains that others can tell them apart. Artists have long had different terms for the many reds they use, here's an example:
http://www.thefloorauthority.com/Gla...Collection.htm
Note that a monitor can't render reds below around 635 so that's obviously not an absolute reference, but should be considered impressionistic at best, but it does show the point of this.

I've always seen a qualitative difference between 671, 650-660 and 635. To me, they map directly to crimson, scarlet and vermillion, respectively. I remembered those colours from a paintbox I had as a kid, I loved the reds especially, and their names. That fascination is maybe why I still like red lasers above all else, and it's the largest part of the visible spectrum we see.

If I walk up to an unknown red laser I not only know what range it's in, I could possibly get closer than that. When I see a scanner in a supermarket I know if it's a 650 or a 670, because my first impression isn't a number at all, I see a quality, not a quantity. It's usually the bold scarlet in the new ones, the deeper crimson in some older ones, and a few are wine dark, close to ruby. Some early low power diodes were as long as 680 or more. To me, 635 is actually ugly, a kind of brash pink-orangey tinted red. The brightness of the red means nothing to me, if I have a real 650 in front of me it's scarlet, it doesn't matter a damn how bright or dim it is, this is a quality, not a quantity, we can resolve it as such. After all, green is just a few more nanometers, right? But it's pretty obviously a different quality entirely and we'd never dispute that. If I turn a scarlet 650 or 660 high, and dim a vermillion 635 down to match in apparent brightness, they're still scarlet and vermillion and I can tell them apart whether they are together or apart.

As an aside to that, maybe related, maybe not, I suspect it might not always be so, but that doesn't invalidate the claim. It may be related to pitch (as opposed to frequency). At times I have absolute pitch, in which case it is equivalent to frequency, near enough. I can often recall a tune, hum it to establish it aloud, or whistle it, then check with a tuning fork or a copy of the original tune if I have it. It's often exact, but frequently not, but what is far more common is it is exactly on the equal tempered scale but transposed a few semitones.

What these things have in common is some kind of conditioning. If you want to tell yourself and others that this has no effect, fair enough, but that's entirely a subjective judgement. The fact that others really can tell these things apart, based on some internalised scale based on past experience, makes it real. If some can do this, then others can. It would only be nonsense or meaningless if no-one could do it.

[Frank]

Here is the photo of 671nm red,enjoy it.

[drlava]

LOL
I would if my monitor were a laser monitor with a 670nm source
http://en.wikipedia.org/wiki/Image:C...sRGB_gamut.png