# How can a Photon have a “frequency”?

I picture light ray as a composition of photons with an energy equal to the frequency of the light ray according to $E=hf$. Is this the good way to picture this? Although I can solve elementary problems with the formulas, I've never really been comfortable with the idea of an object having or being related to a "frequency". Do I need to learn quantum field theory to really understand this?

-

All you need is quantum mechanics, i.e. that nature in the microcosm is dual,sometimes it can manifest wave properties and sometimes particle properties.

It depends on the measurement/experiment if the wave or the particle nature will manifest itself. Electrons manifest this duality: in the two slit experiment their wave nature appears governed by the de Broglie wavelength. Photons do the same too, displaying the wavelength/frequency associated with the collective classical electromagnetic wave.

The classical electromagnetic wave is built out of photons in a consistent way, and you could study this link if you are interested in this more complicated problem.

-

No, sometimes photons exhibit properties of a particle, and other times it exhibits properties of a wave, therefore having a "frequency" and at the same time being a particle.

-
Hi, can you please expand your answer? As it stands now it doesn't really answer the question. – Brandon Enright Jan 29 '14 at 2:10