Next: Night logs Up: No Title Previous: Introduction . We looked at the following data for hints and/or clues on the behaviour of the secondary during the dark run: . the night logs for any mention of problems with the mirrors, . ... focus sweep data for any obvious visual clues for problems with setting the mirror focus, or holding that focus, . ... Astrolog data and the murmur logs for any unusual problems in acquiring data and/or warning messages from the TCC/Galils regarding the mirrors. ...