Those sexy "color ring" RGB controllers....

Does anyone have any experience with the "color ring" RGB LED controllers?

I'm curious about what degree of color selection is actually possible with them, as it appears that the ring would only allow the selection of fully saturated colors. I find the T3-M multi-zone wireless controller made by L-Tec very interesting, but I'm afraid that the color ring wouldn't allow me to set desaturated colors (meaning, rather than a pure hue, a hue washed out towards white).

It seems to have a white area on the ring with yellow and a smidge of blue to either side, which could maybe work as kind of a color temperature adjustment for "white" output, which would be nice, but what of whitish green, pale blue, pink? Are those things out of bounds with a color-ring type controller?

This is all about Color spaces. A flaming sunset has rich, full reds, oranges, and purples. Why don't photos pop the same way? Color Spaces, Dynamic Range, and Color Saturation.

Let's start with the color space we're most familiar with: An LCD/LED screen. Your computer monitor is probably covered with Red, Green, Blue, and White units - They either emit light or selectively block it. A typical pixel will be like this:

It's easy to get Red, Green, Blue, White, and Black - Just turn one element on and all the others off, or something. But in-between colors are tougher. Which colors are in-between? The ones between the "primary" colors in the color space.



Draw a triangle with your Red, Green, and Blue between them. There are limits on which colors can be "reached" from here - In general, you can't get a super-vibrant yellow with Red+Green+white. It will not be fully saturated. Same for purple, cyan, orange, etc. Samsung or someone created a TV with Yellow as a separate element, but it isn't much better.

So if you have FULL brightness control over RGBW, you can reach many colors. But without the white element, or without full control, it'll be hard to make. RGB is worse than RGBW.

I'm pretty familiar with color spaces...

I'm looking at the controller below, and it looks to me like it basically traces the RGB color space triangle as near the edge as the LEDs allow, going from Red to Blue then Green as you go clockwise around, but then makes some squiggly arc inwards from Green through Cyan and White then back out to the edge through Yellow on it's way back to Red. My main inquiry is whether you can get anything off that line. It looks like a fairly two-dimensional control, just that circle and brightness. I'm not seeing a saturation control anywhere, which would be required for full control.

http://www.ltechonline.com/product/img/T3M-RC_big.jpg

Image tags removed see Rule #3 Do not Hot Link images. Please host on an image site, Imageshack or similar and repost – Thanks Norm

All of the nice wireless mult-zone controllers I'm seeing out there are like this, I haven't found any with a hue ring AND saturation/lightness triangle, they all look like they only have hue+brightness. I'd love a ring+triangle type, that's my favorite, but I'd settle for independent RBG sliders, if it were as nice a wireless package as this one.

That looks very much like pure RGB, where you can go "around" the color space, but can't dive "into" it. You need RGBW get real color control. Pure RGB only "sets the mood" without saturation control.

Well, a dimmer option would let you get unsaturated colors, if you have dim ambient white light. But yuck.

It is pretty expensive not to have full control. Another receiver could be connected to white strips instead of RGB, and used to mix in white, but that's kind of cumbersome. I will want a nice white anyways though in addition to colors, and it raises some interesting ideas... If one were to connect three different color temperature white strips to that instead of red green and blue strips, the controller would roll smoothly from one color temperature to the next. It would be psuedo-infinite color temperature control.

Raphion said:

It would be psuedo-infinite color temperature control.

Click to expand...

With the right LEDs, you could simulate early-morning light, noonday, or afternoon. I think you would need some rich ambers and reds to get dawn, and some royal blue for dusk. Check out what the Coral Reef growing guys do with programmable multi-channel drivers.

So many cool ideas; so little money in my wallet.