Limit of Resolution: Blue or Red LEDs that can be brought together

The professor is equipped with either two red LEDs, two blue LEDs or a set of both. The pinpoint sources can be brought together until they are indistinguishable to the students. Due to the wavelength dependency in the diffraction limit the blue LEDs can be observed as being separate closer together than the red. If a quantitative measurement is desire demo staff will mount a ruler to be used.