Date: Sat, 30 May 1998 06:34:03 -0600
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m night report 980529
                            FRIDAY MAY 29, 1998
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
The telescope was opened at about 20:15.  There was a variable thickness of
cirrus most of the night.
We set up on the meridian at the equator.  Data was taken primarily to test
software which works with data from the astrometric chips.  Jon Bakken
stayed up way past his bedtime helping remotely over the phone.
At about 03:30 we stopped and took the camera off the telescope and removed
the optical shims from above the astrometric chips.  Unfortunately the
focus shift was in the opposite direction desired, so we couldn't have the
astrometric and photometric chips in focus at the same time.
Another item on focus, the out of focus images at the start of the night
were extremely astigmatic.  A check of the mirror support system didn't
show anything obviously wrong.  Since it got better as the night went along
it is suspected that the primary may have had enough of a thermal gradient
top to bottom ( as seen when the telescope is parked ), that it affected
the figure until it equalized.
The telescope was closed up once the camera was put into the doghouse at
about 05:30.
                                Dan