I have dedomed a few xmls and notice that the colour of the light changes to may I say warmer tint. Any idea why this is?
As I understand it, it is because of less light being "pulled" out of the LED by the dome so more light will pass through the phosphor. I'm sure someone will come along and explain this in a better way though.
The Dome is there to reduce the inner reflection in the semiconductor/phosphor system. If it is missing, then more light will not leave the led at first try, but will be reflected back onto the phosphor layer, where the remaining blue part of the light gets another chance to be converted to warmer colors.
That’s the short version. The long version (and the reason that i know all that) is a post from DrJones: Flashlight Optics - Dome, Dedoming and Throw
It’s because of this: http://www.youtube.com/watch?v=dWwQqI2BkVc