Trying to understand small increments of light. From a particle perspective, a photon is the smallest increment, dependent on frequency as E=hf. From Maxwell's wave perspective, light propagates as a result of the energy passing between the E field and the B field. The rate at which this occurs gives the frequency. So from a wave perspective, how short can a wave of light be? Less than one wavelength? If I have a source, a radio transmitter, that emits 10 1/4 lambda of light, and 10 lambda is received/filtered/reflected, can the 1/4 thats left when the filter is removed still propagate?