thanks....BMW told me that the CCT was at 5000, but then what would the tint be?, as those are intense some more than normal 4500CCT HID's here in the UK...
thanks.
CCT and tint are different things, even though they are related. Take the spectral power distribution of a white light (From low to high frequency, with output as the vertical axis). Apply a best-fit function to snuggle it into a bell curve characteristic of black-body radiation (There is an equation to do so consistently). That curve is described by a CCT of a certain temperature of glowing blackbody, and a CRI that describes the quality of fit.
Tint is a location in the CIEL*AB color space. What is a color space? Imagine all the colors in the world on a grid. What is the axis of this grid? Colors. We like to use Red, Blue, and Green for it because our eyes do. For any red, blue, and green you can pick, there is a triangle of 'color space' between those colors. Mixing red, blue, and green lights can make light that looks like ALL the colors inside that triangle. (Note that red+green light looks yellow, but isn't the same as yellow photons). 'Tint Bins' are small areas in this color space. Actually, Cree's tint bins are big enough to fit a truck through.
Tint is related to CCT because we perceive tint in white light when it has a bit more of some colors. These could be greenish, purplish, blueish, reddish, and so on. In general, picking higher-CRI and 4000-5000K CCT lights reduces apparent tint. In practice, it depends on which tint bin, which CCT, which power, which temperature, which variation, and which setting the light is viewed under.
Anyway, the short version is that on the highway this will look a bit cold or even bluish, depending on what headlights it is next to. The long version is that it'll look funny whenever the HID and LED do not match what they are near.
