I've been doing a little electrical engineering (outside of my lane a bit). I'm trying to get the RGB values for Edison light bulbs. Can anyone provide me with those?
closed as off-topic by pipe, Dmitry Grigoryev, RoyC, awjlogan, Finbarr Oct 18 '18 at 10:10
This question appears to be off-topic. The users who voted to close gave this specific reason:
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I used Firefox Web Developer Eyedropper to grab the RGB from a photo of an Edison Light Bulb.
A lighter pixel
This is very close to the color when a 2700K 97 CRI LED was reflected off bright white paper: #F4D4AB (244,212,171) just a little less blue.
(245, 212, 131)
I do not believe the LED actually illuminates using the color you see when viewing the filament. The filament LEDs are no different from other lighting LEDs. Many of these "Edison Lights" have Color Correlated Temperature (CCT, e.g. 3000K) and Color Rendering Index (CRI, e.g 80). With that you can get the CIE x,y chromaticity coordinates based on CCT and CRI. Both CCT and CRI are needed although CCT only will suffice. Once you have the x,y chromaticity coordinates they can be translated to RGB.
LED datasheets often have the CIE x,y chromaticity coordinates as shown here:
Using CIE x,y chromaticity coordinates from the datasheet of a 2700K CRI 90 LED (red x,y).
I wrote an SVG app to plot the x,y on a chromaticity diagram to compare two LEDs.
The red x,y are from a Citi CLU036-1205C1-273H5G3 2700K 90 CRI
The blue x,y are from a Citi CLU036-1205C1-30AL7G4 3000K 70 CRI
I used the eyedropper to grab the RGB off the chromaticity diagram for the 2700K 90 CRI.
Using CIE x,y chromaticity coordinates from the datasheet of a 2700K CRI and using a CIE Color Calculator I get:
(253, 172, 90)
#F06F5C 1750K CRI 98
#E2CBAC 3000K CRI 80
#F4D4AB 2700K CRI 97 (244,212,171)
#E96C66 Luxeon Fresh Focus Red Meat
2700K is a very warm light. 97 CRI is very close to (natural) sunlight (CRI 100 = sunlight)
I'm asking for the closest RGB match to the golden glow that an Edison bulb emits
There is no difference between a "Edison Bulb" and any other LED light bulb.
In my opinion a nice warm light is 2700K with a high CRI.
Grabbing the RGB with the eyedropper from the reflection of a 2700K 97 CRI LED off a bright white paper we get this:
2700K CRI 97
Measured with a StellarNet BLUE-Wave Spectrometer
The PPFD is a measurement of the number of visible photons in µmols.
So this PPFD measurement shows exactly what wavelengths are being emitted (as a plant "sees") before they are adjusted for photopic luminous efficacy (human perception).
Slightly lower CRI, more green and less red.
When the number of photons are adjusted for photopic luminous efficacy it is not what most people would expect. This is exactly the same LED being measured (seconds later) with the same spectrometer as the first image with the measurement units flipped from PPFD to Lux.
Examples of Low and High CRI
RGB value doesn't have units. It depends on the specific monitor and GPU combination and calibration.
To measure color, you can measure its temperature, use colorimeter or compare it to a known calibrated color such as a Pantone swatch.
This website has some empirical matching of RGB values to apparent filament temperatures. For a 40W incandescent bulb with a color temperature of 2800K, the suggestion is (255,197,143)
Here is what that looks like (there's quite a bit more blue in it that some other answers):
Here is the table (credit to the above-linked website, above graphic is mine).