The Rayleigh Criterion

The Rayleigh Criterion is a standard for determining the resolving power of optical systems like microscopes and telescopes. It states that two objects are just distinguishable when the light from one creates a diffraction pattern whose central maximum overlaps with the first minimum of the other’s pattern. Essentially, it defines the smallest detail two lenses or eyes can differentiate based on the wave nature of light, setting a limit on the clarity of images. This helps in designing optical systems to ensure they can distinguish features as fine as physically possible.