[sdiy] Controlling LED color shift over time for backlighting etc.

[H.Sergio Alves]

Worked with Barco Indoor and outdoor led panels  (iLite, Olite, MiTrix) and
although they were calibrated at factory we had to perform colour
correction and calibration specifically when in tv studios… tv producers
and photography directors inform us of their colour temperature, hues and
other factors that we would use to calibrate all LEDs of all panels so they
looked the same… in around 10 years working with Barco I’ve sent 4 panels
to manufacturer for replacement of LEDs (rgbw). Their stuff is impressive
and very well engineered. Not cheap at all


On Thu, 26 Feb 2026 at 21:39, brianw <brianw at audiobanshee.com> wrote:

> Interesting.
>
> Is the Forward Voltage drop the only thing that affects color in LEDs?
>
> Also, how long does it take for the Vf to change, and does it vary that
> much between components in the same batch? The advertisement mentions
> drift, which implies a long-term adjustment to keep individual components
> at the same current, but there is no mention of whether this is an
> effective way to match color between different components.
>
> My understanding is that cheap LEDs do not match each other in color. LED
> manufacturers offer binning at an extra cost, where they test things like
> the wavelength and group specific components into narrow ranges. If you
> want to design a product with consistent LED color, you would need to start
> with higher-priced LED components that have been tested to match each other
> in output. Usually the part number for the LED has a suffix to indicate the
> bin, and the data sheet cites the nanometer wavelength range for that bin.
> The part is often available with no suffix, meaning that they skip the
> testing phase and pass the savings on for cheap products.
>
> All things considered, I think it's important to know which factors have
> more effect on the color.
>
> Brian
>
> p.s. I have noticed that large LED displays often have hue shifts that are
> clearly visible between individual panels. My interpretation is that
> someone went cheap and didn't bother to manufacture all panels with
> narrowly-matched RGB colors. I suppose that could be corrected with color
> sensors and modifications of the image content, but it seems smarter to
> start with hardware that matches at the physical manufacturing stage.
>
>
> On Feb 26, 2026, at 6:54 AM, drheqx wrote:
>
> Hi All,
>  If you are designing a system with LEDs as ambient lighting this device
> might offer a good solution to control color drift over time. The concept
> is very good and I am sure there are other ways to do this, but in the case
> of things like illuminated pads color drift and variation across a grid of
> pads can be very noticeable and this might be an effective way to control
> that drift.
>
> https://www.novosns.com/en/en_ambientlightingdriver-4546
>
> Mike
>
>
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