Hi Let's stick to the classical limit. We have 2 monochromatic light waves of same intensity. Let's say one is blue and one is red. Now this means the individual photons of the blue light have more energy(obviously, higher frequency) and the red light photons have lower energy. But since the two light waves have equal intensity, they have the same energy arriving/second.. Right? I think this part is obvious. This then means that the red light wave has more photons and the blue light wave has fewer photons. Well let's move on to amplitude of the light wave, now this sort of scales with the intensity squared so these two light beams should have the same Amplitude? But Amplitude can also be seen as a function of the number of photons.. Here in lies my current confusion. Sorry if this is so simple. Anyone know of a basic way to get around this and stay consistent? Either the two light is going to have different amplitude or the same amplitude while the have the same intensity but different frequencies.