Flexure of Sofi objective SF with focal elongator measured at 24 positions. Inner circle shows movement of point image on detector for one full revolution. Position of closed cycle cooler indicated on rotated squares as seen standing in front of entrance window. Flexure is 12.3 pixels peak to peak at the detector or 165.32 mm at telescope focus pointing in direction of gravity. Internal flexure of Sofi objective LF measured at 24 positions.
Inner curve shows movement of point image on detector for one full revolution.
Position of closed cycle cooler indicated on rotated squares as seen standing in front of entrance window. Flexure is 1.2 pixels peak to peak at the detector or 64.63 mm at telescope focus. The downward shift vectors are measured without counterweights the upward vectors with a counterweight of 15 kp. Pixel transfer function determined with shot noise method. Pixel transfer function determined with shot noise method.