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Thread: My "Golden Eye" does not lie

  1. #1
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    Default My "Golden Eye" does not lie

    Anyone else compare the colour output of 445 LD vs.473 DPSS ?? I do not see much difference at all ???? Comparing a 473@200mW to a 445@1300mW. The output percieved luminosity is equal....which fits with the eye response curve ( See chart below pulled from Sam's Laser FAQ).

    In my opinion...with corrective optics....445 IS the way to go...on a new projector build....but for an existing build ??? I do not know that I am going to "Open up the hood" ..yet another time...not for a single 445LD....
    Perhaps "Projector#2".....Dual 445LD, Quad 638LD and LW green....Sheeeeze !!! what a Money Pit this Hobby is !!! !!! Anyone else see or NOT see much difference 445 vs 473....in the color area....not beam quality....DPSS is still the SS King there !!

    CDBEAM





    Wavelength Response Color Typical Source/Application
    -------------------------------------------------------------------------------
    350 nm .00001? UV
    380 nm .0002 Near UV
    400 nm .0028 Border UV Nichia violet GaN laser diode
    410 nm .0074 " "
    420 nm .0175 Violet
    442 nm .0398 Violet-blue Violet-blue line of HeCd laser
    450 nm .0468 Blue
    457.5 nm .0556 " Blue frequency doubled Nd:YVO4
    457.9 nm .0562 " Blue line of argon ion laser
    473 nm .104 " Blue frequency doubled Nd:YAG
    488 nm .191 Green-blue Green-blue line of argon ion laser
    500 nm .323 Blue-green
    510 nm .503 Green Emerald green line of copper vapor laser
    514.5 nm .588 " Green line of argon ion laser
    532 nm .885 " Green frequency doubled Nd:YAG or Nd:YVO4
    543.5 nm .974 " Green HeNe laser
    550 nm .995 Yellow-green
    555 nm 1.000 " Reference (peak) wavelength
    567 nm .969 " Green line of Helium-Mercury laser
    568 nm .964 " Y-G line of some krypton ion lasers
    578 nm .889 Yellow Gold line of copper vapor laser
    580 nm .870 "
    594.1 nm .706 Orange-yellow Yellow HeNe laser
    600 nm .631 Orange
    611.9 nm .479 Red-orange Orange HeNe laser
    615 nm .441 " Orange line of Helium-Mercury laser
    627 nm .298 " Orange line of Gold Vapor Laser
    632.8 nm .237 Orange-red Red HeNe laser
    635 nm .217 " Laser diode (DVD, newer laser pointers)
    640 nm .175 " "
    645 nm .138 " "
    647.1 nm .125 Red Red line of krypton or Ar/Kr ion laser
    650 nm .107 " Laser diode (DVD, newer laser pointers)
    655 nm .082 " Laser diode
    660 nm .061 " "
    670 nm .032 " Laser diode (UPC scanners, old pointers)
    680 nm .017 "
    685 nm .0119 Deep red
    690 nm .0082 "
    694.3 nm .006 " Ruby laser
    700 nm .0041 Border IR
    750 nm .00012 Near IR
    780 nm .000015 " CD player/CDROM/LaserDisc laser diode
    800 nm 3.7*10-6 " Laser diodes for pumping Nd:YAG, Nd:YVO4
    850 nm 1.1*10-7 "
    900 nm 3.2*10-9 "
    1,064 nm 3*10-14 " Nd lasers (including YAG)
    1,523.1 nm 0.0000 " IR HeNe laser
    3,390 nm 0.0000 Mid-IR IR HeNe laser
    10,600 nm 0.0000 Far-IR CO2 laser
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  2. #2
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    Default

    As far as I'm concerned 445nm had me sold the instant I saw how rich it is by itself, and how it transfers that richness to every color it's blended into. To my eyes there is a huge difference between 445nm and 473nm, with 473nm appearing almost teal in comparison. 473nm will never, ever find it's way into a projector of mine again.. but that just my opinion.

  3. #3
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    as mentioned before by someone, 473 looks greenish next to 445. Also noticed that the beam is more visible but less bright, if that makes sense. In daylight I'm always surprised to see the 445 beam, even when turned down to 300ish mW. In smoke it isn't necessarily brighter than my 150mW 473.

    That is about as un-scientific as I can get

  4. #4
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    Quote Originally Posted by CDBEAM View Post
    The output percieved luminosity is equal....
    I assure you while that might be the case on paper its absolutely not the case in practice

    I have 350~400~mW of 473 mixed with 1.2W of 445 and the 445 blows the 473 away

  5. #5
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    Default I assure you....I am right....haha....in my " EYE"

    Well....what I meant to say was that in MY personal perception...I perceived the the 445nm @ 1300mW to be of equal colour and intensity to the 473nm @ 200mW.....Both lasers were directed at a white sheet of foam core board at a beam termination distance of 9 meters.
    The ambient lighting was low level incandescient

    I suppose that the scotopic vision factor could have some impact. I am surly not well read on " Receptive Field " vision study....but....none of this really matters !!! We are all... each individuals concerning the area of perception !!!! So....this is what I saw....

    ....Anybode else see this ??????...mmmm...or is this a result of my....mmmm...." Timothy
    Leary" years ???? HAHA....and...

    CDBEAM
    Attached Thumbnails Attached Thumbnails monkeys_thinkMYMY GOLDEN EYE.jpg  

    Last edited by CDBEAM; 09-16-2010 at 20:17.
    Beam Axiom #1 ~The Quantum well is DEEP ! Photons for ALL !!
    .
    Beam Axiom #2 ~Yes...As a matter of fact...I DO wear tinfoil on my head !!
    .
    Beam Axiom #3 ~Whe'n dout...Po ah Donk awn et !!
    .
    Beam Axiom #4 ~A Chicken in every Pot, and a Laser Lumia in every Livingroom !!
    .
    Beam Axiom #5 ~"Abstract Photonic Expressionism"....is "Abstractonimical" !!
    .
    Beam Axiom #6 ~ "A Posse ad Essea" ~ From being possible to being actual ...is the beam target !

  6. #6
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    Default tracking thread

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    BEAMANN (GODSLIGHT SHOWS)

  7. #7
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    Quote Originally Posted by CDBEAM View Post
    Well....what I meant to say was that in MY personal perception...I perceived the the 445nm @ 1300mW to be of equal colour and intensity to the 473nm @ 200mW.....Both lasers were directed at a white sheet of foam core board at a beam termination distance of 9 meters.
    Were they scanning, or were you just looking at the bright spot? Remember that the human eye will saturate at relatively low power levels, and once you reach that point it's very hard to tell differences in luminosity even for large changes in power.

    Get them both scanning side-by-side in some fog and then look at the plane of light produced in the air and see which one is brighter. I think you'll find that the darker 445 nm blue stands out much more in that example. (At least, that's what we saw at SELEM.)
    The ambient lighting was low level incandescient
    Then you were either in the photopic, or more probably the mesopic vision range. Scotopic doesn't kick in until you're in a darkened room with just a small amount of light leaking in. (Think being outside in your yard at night with no house lights on and a full moon overhead, plus some light pollution from the city lights nearby.) Still, as you move away from Photopic vision the color peak shifts from 555nm towards the blue portion of the spectrum. Once you're in full Scotopic vision, the color peak is very close to 445.

    Another thing to realize with these diodes is that using 445 does change the color pallet you have available. While Electrofreak is correct in that mixing 445 with other colors does give you a very rich range of hues, there is a trade off. You lose your cyan color. Even with mixing 445 and 532, it is *not* possible to generate a cyan or "teal" color with more than 50% saturation. (While I've already seen this in person in side-by-side tests, you can look up the numbers on the CIE color chart if you don't believe me.)

    Why is this a problem? Because lots of existing ILDA artwork uses that cyan or teal color for things like a blue sky, and it looks funny when it's drawn with the darker blue of a 445 nm diode. (Remember that a lot of that artwork was drawn when argon was used for blue, with the 488 nm line in mind.) True, many old school laserists have been trying to get away from that cyan color for some time now, but for a lot of artwork, that fully-saturated cyan is a major part of the effect, at least in my mind.

    OK, call me a purist, but I *like* having the 473 line, at least in a graphics projector. Truly, the best of both worlds would be to have 473 and 445 in the same projector, but I don't know if I'm willing to go through the hassle of adding it to my graphics unit. Assuming you already have a 473 unit, and assuming you don't need any more blue power in your projector, I'd rather leave the 473 in place than remove it in favor of a 445.

    Now, I will admit that I will be building 2 beam projectors in the future (one is almost finished), and they will both have the 445 blues in them. For beams, I don't see the point in adding 473. Having a fully-saturated cyan isn't as important for beams as it is for graphics.

    And finally, I do realize that we are more likely to notice this than the untrained eye of a spectator. Your audience may never notice the difference. Nevertheless, for my tastes, I like having the 473 in a graphics projector. Your mileage may vary.

    Adam

  8. #8
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    Quote Originally Posted by buffo View Post
    I don't know if I'm willing to go through the hassle of adding it to my graphics unit.
    LW blue PBS... passes 473 no problem, reflects 445 no problem.. its easy I assure you

    then you just setup the 445 on the dark blue pin, whole new world of colors

    Quote Originally Posted by buffo View Post
    For beams, I don't see the point in adding 473. Having a fully-saturated cyan isn't as important for beams as it is for graphics.
    I'm going to have to go ahead and sort of disagree with you there... mmkay?

    but ya, even in beam shows I can definitely see the pangolin using the different blues for stuff and it does make a difference... now, from a cost point of view, 473 in a beam projector makes little sense

  9. #9
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    Hi Frank!

    It's not the problem with finding a cube so much as just the hassle of ripping the optical table out to add the 445 module. Plus, I don't have a lot of red headroom, so if I add more blue to my graphics rig I'll rapidly run out of red. (Got plenty of green though!)

    Still, who knows? Maybe in the future I'll do it. But right now I've got too many other projects vying for my attention.

    As for the beams, I agree it would be nice to have 473 in there, but I don't think the impact is nearly as important. (If the beam is supposed to be cyan, and it looks a little washed out or a little darker, no one will really mind, but if the sky in a graphics show is too dark, people are more apt to notice it.)

    But yeah, if I had the cash, I would have a projector like yours. That thing is friggin' awesome dude. Maybe when I hit the lottery...

    Adam

  10. #10
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    Quote Originally Posted by buffo View Post
    mixing 445 with other colors does give you a very rich range of hues, there is a trade off. You lose your cyan color. Even with mixing 445 and 532, it is *not* possible to generate a cyan or "teal" color with more than 50% saturation. (While I've already seen this in person in side-by-side tests, you can look up the numbers on the CIE color chart if you don't believe me.)
    I don't do graphics much so I'm not sure about how things look there, but I've had no trouble getting a pretty vivid cyan when doing beams.. I would imagine that the most ideal setup would be sources providing ROYGBV for a full spectrum.. that would likely give the richest possible palette provided they were each individually controllable.. but that's a lot of complication that might not be necessary for all applications. Much of this is dependent on the eye of the beholder.. there's so much talk about balancing, but I don't even think that it's possible to put a definite quantity or value on just what good color balance is. There are things that are obvious about top-notch, well-balanced systems when compared to systems with poor balance, but once you begin getting into the fine adjustments there's so much variation in just what people like to see.

    I think more attention should be put into leveling the color balance over a group of projectors, since frequently I see video of groups of full-color systems each with a different color balance. It would look much better if they all matched IMO.
    Last edited by ElektroFreak; 09-19-2010 at 19:44. Reason: spelling

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