Screenshot of the tracking camera image obtained after centering a stellar companion on the science fiber (roughly at the center of the image). The primary star is located in upper left of the companion. The four broad spots forming a square are the images of the feedback fibers. Their specific size and shape are due to the optics in the feedback channel of the FIM, and in particular to the use of a corner cube for the retro-reflection. The center of each feedback fiber is obtained with a 2D Gaussian fit on the brightest peak of their image.