English: Simulated diffraction pattern from an aperture 0.15mm in diameter illuminated by a plane wave of wavelength 0.5 micron. The screen is positioned at the following distances in order: 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 5, 8 mm from the aperture. The amplitudes are computed via Fresnel integral over the aperture function (on the first frame). The reference bar at the bottom is representing a linear increase in energy from left to right.