I noticed that simple fixtures like pure rgb and just a dimmer works ok. But more complicated that have RGBW plus seperate dimmer are treated to have RGB and W is treated as a dimmer. The dimmer has no effect. Example Stairwille PAR56 RGBW in full mode.
Is this a known simplification or perhaps a bug I could try to fix?
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the problem is that it's not easy to map RGBW (or RGBAW for that matter) to RGB so that the colors are consistent with plain RGB fixtures. One way could be to sacrifice some color range and map RGB to 0-let's say 230, and use the remaining top 25 as margin to simulate the W light.
All audio amplifiers have a knob that goes up to 100% (unless you are a Wayne's World fan - 110%!). A 1000W amp is louder than a 10W version.
What you see on screen is similarly a ratio of the 100% setting (0-255). It matters not if the lamp is a 4W PAR RGB or a 4kW laser. My view is that a full primary colour (eg. red) should be 255, with other colours being added as the white or amber setting is turned up, thus reducing the saturation of the primary colour(s).
At the end of the day you are limited by the gamut (brightness range) of the monitor in use and the above technique is a form of auto-exposure similar to a camera's. What is important on screen is the colour of the output; the brightness is secondary and generally unachievable on a computer screen.
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Looking at the original poster's comment, I think they are trying to use an RGB+dimmer fixture definition to control an RGBW+dimmer. Hence, the channels won't match.
Karri, please tell us what devices you are using and which fixtures you have chosen.
Cheers
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I am running a small theatre with 5 Stairville PAR 56 LED RGBW, 1 Eurolite RGB Flooder and 4 white old fashioned white spots.
The thing is that I try to design light scenes at home and build up the play. While doing this I noticed that I must crank up WHITE in order to see any color at all. The DIMMER does not affect the RGBW lights at all. It appears that the monitor believes that I am using 4 channel mode for these lights when in reality I use the full-mode.
But this is a very small annoyance. I just thought of fixing this to give something back to this excellent community.
I just found out that this is a fixture problem. The similar fixture with RGBA works as expected. Or actually Amber color does not show.
The strange thing is that by taking Stairville-LED-PAR56-MKII-RGBA.qfx and changing Amber to White I get a working fixture for Stairville-LED-PAR56-MKII-RGBW.qfx
I will study this for a while and perhaps make a pull request for the corrected light fixture.
The monitor does not show Amber color or White color. But that is a minor inconvenience.
Last edit: Karri Kaksonen 2015-03-29
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as you already found, the problem is in the wrong fixture: the white channel does not have
specified color, so it is treated as dimmer channel. If you set the color to white, while leaving the intensity group as it is, the fixture should work fine. Change the fixture definition either by using fixture editor, or open the qxf file in a text editor and add <Colour>White</Colour> tag inside <Channel Name="White"> tag.
Then there is second problem, that 2D monitor does not display white nor amber color and that is what I've referenced in my previous post.
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Thanks. The colors are uncalibrated in any case so a rgb simulation is enough. It would be nice to have a strong blue when only the blue is active and a lighter blue if white + blue is active. Perhaps "white" could be added as a real color to the color simulations. It could be treated as washing out the saturation.
I just noticed that there is already a method QColor::fromCmyk(c, m, y, k) where k=0. Perhaps we could also have a method Qcolor::fromRgbw(r, g, b, w) where white is zero by default. In cases where you have white or amber leds you could add a fourth channel to the simulation. The difference between amber and white has to do with color temperature so they could both be treated by something between white and amber.
Last edit: Karri Kaksonen 2015-03-31
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Thanks. I am happy with this. We really don't need the white for simulations. The basic color is enough at planning stage. We have to fine tune the color scenes and the directions for every fixture before the show anyway.
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I noticed that simple fixtures like pure rgb and just a dimmer works ok. But more complicated that have RGBW plus seperate dimmer are treated to have RGB and W is treated as a dimmer. The dimmer has no effect. Example Stairwille PAR56 RGBW in full mode.
Is this a known simplification or perhaps a bug I could try to fix?
Hi,
the problem is that it's not easy to map RGBW (or RGBAW for that matter) to RGB so that the colors are consistent with plain RGB fixtures. One way could be to sacrifice some color range and map RGB to 0-let's say 230, and use the remaining top 25 as margin to simulate the W light.
The code to calculate the color is here.
There are some related threads in the forum archive 1 2.
All audio amplifiers have a knob that goes up to 100% (unless you are a Wayne's World fan - 110%!). A 1000W amp is louder than a 10W version.
What you see on screen is similarly a ratio of the 100% setting (0-255). It matters not if the lamp is a 4W PAR RGB or a 4kW laser. My view is that a full primary colour (eg. red) should be 255, with other colours being added as the white or amber setting is turned up, thus reducing the saturation of the primary colour(s).
At the end of the day you are limited by the gamut (brightness range) of the monitor in use and the above technique is a form of auto-exposure similar to a camera's. What is important on screen is the colour of the output; the brightness is secondary and generally unachievable on a computer screen.
Looking at the original poster's comment, I think they are trying to use an RGB+dimmer fixture definition to control an RGBW+dimmer. Hence, the channels won't match.
Karri, please tell us what devices you are using and which fixtures you have chosen.
Cheers
I am running a small theatre with 5 Stairville PAR 56 LED RGBW, 1 Eurolite RGB Flooder and 4 white old fashioned white spots.
The thing is that I try to design light scenes at home and build up the play. While doing this I noticed that I must crank up WHITE in order to see any color at all. The DIMMER does not affect the RGBW lights at all. It appears that the monitor believes that I am using 4 channel mode for these lights when in reality I use the full-mode.
But this is a very small annoyance. I just thought of fixing this to give something back to this excellent community.
I just found out that this is a fixture problem. The similar fixture with RGBA works as expected. Or actually Amber color does not show.
The strange thing is that by taking Stairville-LED-PAR56-MKII-RGBA.qfx and changing Amber to White I get a working fixture for Stairville-LED-PAR56-MKII-RGBW.qfx
I will study this for a while and perhaps make a pull request for the corrected light fixture.
The monitor does not show Amber color or White color. But that is a minor inconvenience.
Last edit: Karri Kaksonen 2015-03-29
Karri,
as you already found, the problem is in the wrong fixture: the white channel does not have
specified color, so it is treated as dimmer channel. If you set the color to white, while leaving the intensity group as it is, the fixture should work fine. Change the fixture definition either by using fixture editor, or open the qxf file in a text editor and add <Colour>White</Colour> tag inside <Channel Name="White"> tag.
Then there is second problem, that 2D monitor does not display white nor amber color and that is what I've referenced in my previous post.
Thanks. The colors are uncalibrated in any case so a rgb simulation is enough. It would be nice to have a strong blue when only the blue is active and a lighter blue if white + blue is active. Perhaps "white" could be added as a real color to the color simulations. It could be treated as washing out the saturation.
I just noticed that there is already a method QColor::fromCmyk(c, m, y, k) where k=0. Perhaps we could also have a method Qcolor::fromRgbw(r, g, b, w) where white is zero by default. In cases where you have white or amber leds you could add a fourth channel to the simulation. The difference between amber and white has to do with color temperature so they could both be treated by something between white and amber.
Last edit: Karri Kaksonen 2015-03-31
I've fixed the fixture (and some others) in the git.
Thanks. I am happy with this. We really don't need the white for simulations. The basic color is enough at planning stage. We have to fine tune the color scenes and the directions for every fixture before the show anyway.