LouieAtienza, I think one concept you are missing is that of luminance. This is a measure of the surface brightness (of the LED) and it is important in the determination of beam intensity or throw (intensity in cd is equal to luminance times apparent reflector area). The luminance of LEDs does not vary with angle; the reason the intensity goes down as you go to the side of the LED is because the apparent area decreases. See here for some explanation.