Upper panel: subframe centered on Venus at the epoch of second contact, during the transit ingress, from a single SDO/HMI image obtained at 617.3 nm (Fe I absorption line). Lower panel: SDO image with extreme contrast stretch, to show the aureole. The radial direction of the flux measurement is shown, with the area at + 49° that is considered for comparison to SOIR. The value of f in the bottom left corner is the linear fraction of the Venus diameter projected outside the solar limb.