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Thread: The Perfect Colours, Have I just cracked it?

  1. #1
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    Default The Perfect Colours, Have I just cracked it?

    Hi,

    Been thinking about this a lot lately. Probably only Frank or Bridge who can do this because of resources, but how useful would it be to have a colour vs wavelength card made up of photos to show the different mixes?

    If your wondering why I've put this in the advanced section read on....

    One of the things that has occurred to me is that everyone on here uses either 660nm or 635nm Red or 473nm or 445nm Blue. Some may use a mixture, but nearly always at the same fixed ratio. However, is this really giving the perfect colours or is everyone missing out by never knowing the blends in between?

    When you look at the colours used by some of the professionals such as Hugo, they bear little resemblance to the fixed colours used here:













    All of which makes me think, with the greatest respect that maybe we're all using the wrong approach with fixed wavelengths / mixes.

    You see with the reds eg. everyone is using either one of the fixed wavelengths or a mixture of the two based on a fixed ratio to do with the brightness of each. However, who's to say this is actually producing the perfect red?

    It seems to me that the best way to find the perfect red would be to start with two modules of say 400mw of each colour mixed together with a dicro / cube etc. Start the 660nm at 0 mw and the 635nm at 400mw. Then step the 660nm up in 20mw increments all the way to maximum power recording photos on the same exposure settings all the way up the scale. Then reverse the situation and start the 660nm at 400mw and the 635nm at 0mw and repeat the stepping and recording.

    The point to this is that with the fixed ratios, currently used, no-one actually knows if they have the best red, and some professionals efforts would suggest not, but the best red may actually lie somewhere between the fixed ratios as a blend that simply isn't ordinarily tried. The same can be said of the 2 blue colours.

    To my mind given that everyone has a personal preference, the best way to discover the best colour and make comparisons would be to make a colour card of each wavelength at various different mixes and then make a visual comparison to establish the best mixing ratio. With analogue lasers, maybe this could then be either set in the software or if impossible, it would at least give a means of working out what size modules of each wavelenght to put into a projector.

    The yellow I have to confess is probably beyond most as Hugo uses a Coherent OPSL dedicated yellow as I understand it which is mega $.

    However, the other colours might only be trial and error away from the normal blends.

    Or to put it another way, the perfect projector might not be RGB but RRGBB or RRGBBY for the very rich.

    What do you reckon? Am I barking up the wrong tree, or is everyone possibly missing the best colour blends simply by sticking to the fixed ratios based on brightness theories?

    Is anyone with the resources willing to put together a colour card using stepped powers?

  2. #2
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    When it comes to pure wavelengths of visible light, coming from a laser, you take what you can get!

    660nm is a better red than 635, but 635 is easer to see, so it takes a lot less power.

    Fortunately, human color vision can easily be tricked!

    As long as you have a good source of red, green and blue (and maybe violet) AND you can analog modulate all of these wavelengths, you really can make almost every color the human eye can see.

    Take a look at your computer monitor!

    There is nothing there more than red, green and blue!

    I suspect the biggest part of the razzle-dazzle of the BIG laser shows is PURE POWER!

    James.

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    As James mentioned, the color "blends in between" come from the having lasers with a wide, smooth, modulation range, and software written to support the hardware's capabilities. With the right combination of software and just 3 lasers, virtually millions of color shades are possible!

    The trade-off for us hobbyists often comes in the form of "power vs. color". To put it in VERY simplified (relative) terms, green is cheap, blue is expensive, and "usable" red (beam specs with diameters that actually fit the scanner mirrors) is somewhere in between. With the right software, we can get a pretty good "white" balance, and subsequently a very nice, wide color palette, with just about any combination of lasers in the three colors. Unfortunately, what frequently happens with a lot of us hobbysists is we wind up having to "dial back" the power of our (often) over-powered green, and sometimes red, lasers to white-balance the lower-powered, expensive blue laser. The result can be a VERY nice wide-range color combination for graphics, but less power overall.

    DMX-only projectors probably are going to be VERY limited in the color combinations available - in fact, unless it is set up for analog modulation, you may have only 7 colors available, since that is all you can get with 3 lasers either "on" or "off" (TTL modulation) with no in-between shades. Software/hardware packages like Pangolin's LD2000/QM2000 or FB3 with LAStudio, and others, are designed to give you full control of the lasers' capabilities across their full analog range. In fact, the LD2000 lets you assign different color palettes to laser frames as needed, so you could feasibly incorporate nice color-balanced graphics and full-power beam shots in the same show.

    Like James said, we take what we can get (afford!!), and make the most of it with software - at least until we hit the lottery and can afford those multi-watt full color mega-buck lasers used by the pros!! Besides, those would be WAY to bright to use in my garage...
    Last edited by Stuka; 10-11-2008 at 19:13.
    RR

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    Sweet.....

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    I understand what James is saying but I think it perhaps misses the point.

    You do get all the colours by mixing the RGB but what I'm saying is, is everyone using the best Red or Blue wavelengths to make up the R and B in the RGB?

    Is it not possible that by using fixed wavelengths the modules come in or fixed ratios to create the R or B by mixing 2 wavelengths of each based on brightness ratios, we are in actual fact missing out on the best R or B simply because the best R or B is made up of a blend of the 2 fixed reds or blues that simply isn't normally tried? eg the red normally used by builders is either 660nm or 635nm, or 660nm AND 635nm mixed at eg. a power ratio of 2:1, when in fact the best red might in fact be produced with eg 219mw 635 mixed with 395mw 660 which is a ratio of 1:1.80365 and thus falls outside that normally tried?

  5. #5
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    the problem is the usual cameras do not have perfect gamma, nor do printers. Short of a ion laser using a gas mix with a pcaom, you pretty much have to take what you have budget for, and hobby grade lasers are notoriusly nonlinear. So no, having a color card made up wont do it. besises, even eyes differ, your idea of a pure red might look brownish to me. There are a lot of other factors, I'm assuming you want beams, but also haze density, laser rise and fall time, quality of software used , background light levels, is the eye scoptopic, mesotopic, or photopic during the test etc. what looks great to a scotopic eye might look bad to a photopic eye as the sensitivity peak shifts more toward the yellow.

    Steve
    Last edited by mixedgas; 10-11-2008 at 15:19.

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    Wow those pictures seem to show that every audience member has their own personal beam coming straight at them...!!

    Hope this system has the Pangolin PASS system on it (or similar)..

    Ray
    NZ

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    Quote Originally Posted by Pitts View Post
    Wow those pictures seem to show that every audience member has their own personal beam coming straight at them...!!
    That was my reaction too!

    I've been scanned...... once.

    I didn't like it.

    James.

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    Just taking my own thread slightly off topic to answer your concerns -

    Thats Awakenings, like I said elsewhere, Hugo is a genius at exposure limits vs shows. He's a very senior ILDA member.

    Here's some hi res video of his shows - awesome!

    http://www.overexposure.nl/videos_pa...art%202008.wmv

    (mostly 2nd half of vid) http://www.overexposure.nl/videos_pa...gssept2007.mp4
    Last edited by White-Light; 10-11-2008 at 16:10.

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    Quote Originally Posted by James Lehman View Post
    That was my reaction too!

    I've been scanned...... once.

    I didn't like it.

    James.

    every time when someone posts pictures or video files from dutch rave's the crowdscanning safety "discussion" starts.

    The pictures are from the dutch awakening rave.
    Our country has alot of these extremely big rave's a few times every year.
    These party's generally have 10.000 to 25.000 visitors every event.
    The biggest event Sensation has 45.000 visitors.
    That in a country of 16 million people would mean that alot of my friends have to be blind or have servere eye damage from years of visiting these raves.

    I personally don't know anyone who has problems or have complained about laser exposure at one of these rave's.
    Alot of them know the defenition of laser and the dangers.

    As a photographer i know that pictures/video often exaggerate danger.
    Shuttertime's, aperture and used ISO can do unbelevable things to a picture. (as do saturation and colorcorrection for colors)


    One of the quote's from a recent topic on an Hugo laser "show"

    Quote Originally Posted by Jem View Post

    If it's a show done by Hugo Bunk I doubt there will be a flame post coming. I'm sure he will have done his homework and that show will have been calculated to be safe. He has too much of a reputation at stake to even consider doing anything remotely unsafe.

  10. #10
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    Most big guys are using 640nm red lasers

    Those laser also got much better beamspecs compared to 635nm, and much brighter than 655nm, Next they are using 445nm Blue, with this color you can make very nice dark purple colors.

    So take a
    4W 640nm laser
    2W 445nm laser
    2W 525nm laser

    A nice cambridge set

    and you can make the most of the same colors as the pro's.

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