diffraction limit

The diffraction limit refers to the fundamental restriction on the resolution of optical systems like microscopes or telescopes caused by the wave nature of light. When light passes through a small opening or around an object, it bends and spreads out—a behavior called diffraction. This spreading sets a limit on how finely details can be distinguished; objects closer together than this limit appear blurred or merged. Essentially, diffraction defines the smallest detail an optical device can clearly resolve, shaped by the wavelength of light and the system’s design, preventing perfect imaging of extremely tiny structures.