Recently in the dedomed Nichia 219 thread I experimented with a colour checker card to get an idea of how colours appear with different types of leds. The colour checker is not exactly meant for this kind of application, but I believe it is a nice way to see not just the tint of a light source but also what it does to the different colours.
I found it was difficult to get it right, had to digitally correct the images to match what I see in real, and was still not pleased with the results. Not only I did not get the colours right, but the dynamic range of computer monitors is not sufficient to show everything that is going on in real life (the brightest colour tones have much more 'colour depth' in real life, clear differences between leds in real life show less on screen.
I have now tried a different camera (a Sony DSC W200) and that went much better. Although the dynamic limitations of computer images and monitors are still valid, at least the colour tints on screen matched the real tint well without digital corrections. I find it a very good camera myself, Zeiss lens etc., but it is certainly not comparable to a good reflex camera with big sensor, and it does not produce RAW images (I do not own such a nice camera :-( ). Nevertheless I was so pleased with the results that I want to show them to you, I added some more light sources above the ones from the dedomed Nichia219 thread.
One thing that you must be aware of when viewing these colour charts is that LCD-screens (most of you will use one) are very sensitive to viewing angle: a slightly different angle will already influence not only brightness, but also colour tints. Two identical charts placed on a different hight on your screen will look different. (The oldfashioned cathode ray tube based monitors do not suffer from this)
Some other considerations...
All setting on the camera were fixed, exept exposure, I needed to vary that to compensate for the differences in brightness of my light sources (mostly flashlights). I did an experiment to check the influence of different exposures of the camera: I made two images with the same flashlight, one on a 25% PWM setting, one a 100% setting. The automatic expose of the camera did not fully compensate that, the 25% picture is just a bit dimmer. I then digitally corrected that (by just adjusting the digital 'exposure' setting of the Mac Preview application), and the the 100% image was very precisely reproduced:
Nevertheless in the following charts I did not do any digital corrections, these are the images just as they came from the camera. One exeption: the 9x5mm-led flashlight was so dim that I had to digitally adjust exposure a bit to make it comparable to the other charts.
The dark frame that contain the colour tiles also show a varies tone, depending on the light source, that influences the whole appearance of a given chart. Especially the daylight charts show a lighter coloured frame (because the angle of the lightsource compared to the chart was smaller). I guess it would have been best if I had made the frame the same black in every chart. I'm sorry that I did not do that, so you will have try to look at the tiles while ignoring the frame. EDIT: in the meantime I took the effort of making the frames black, in post #2 are the same charts with black frames , and that really helps looking at them :-)
EDIT2: I improved the daylight pictures that had a haze over them, and added the MT-G2 5000K and 2700K in post #16.
With all their limitations, these charts gave me already some insights I did not have before. One is that the Nichia219 has a warmer tint compared to daylight than I thought it would have, even direct sunlight is quite 'cool white'. Another insight is that some of us here (including me) are really really very spoilt tint snobs: as you can see, all lights, including the 9x5mm chinese generic el cheapo led light, gives off a white that shows all colours ok, what are we whining about? ;-) That said, this chart is not the one that shows subtle skin tones and other sensitive tint differences of nature, perhaps to compare those high CRI light sources a different colour chart that shows that would be better.
Please do not watch the charts before reading the above, the information they contain is limited and I probably have not even mentioned every flaw of them: