Illustration of the raw contrast as a function of separation to the star for various τ₀, ranging from 12.5 ms (black) to 1.25 ms (red). From bottom to top, the curves are for turbulence coherence times of 12.5, 10, 7.5, 5.0, 4.0, 3.0, 2.5, 2.0, 1.5, and 1.25 ms. The solid lines show this along the wind direction, and the dashed lines show it along the perpendicular direction. For comparison, the gray dash-dotted line shows the raw contrast (azimuthal mean of the image) of a SPHERE-IRDIS H2-band (centered on 1.59 μm) image under median seeing, airmass, and long τ₀ ∼ 9 ms.