Observed intensity variation along the slit for FOV blocked in F1 (black), blocked in F2 (green), and for the slit across the limb (blue). The purple lines at x,y = (0′′,100%) denote a simulated sharp edge that after convolution with the kernel at the right yields the red curve. The inlet on the left shows a magnification of the stray-light tail region. The derivative of the observed intensity variation for the FOV blocked in F1 is overplotted over the kernel as an orange line.