A report on recent Hartmann testing of the 3.5m is now available at: anonymous ftp: ftp.astro.washington.edu in users/diercks/hartmann/hartmann_10_9_95.ps and on "the web" : http://www.astro.washington.edu/stubbs/aporeports.html Abstract: A classical Hartmann test was performed on the entire optical train of the 3.5m during engineering time on October 9, 1995. Results indicate that the optics {\bf alone} produce images with a FWHM of .59 arcseconds and that 80\% of the encircled energy falls within .81 arcseconds. The specification for telescope contribution to image FWHM for the 3.5m is .24''(MILT proposal). The actual image size on a detector is substantially larger than .59'' due the additional degradation caused by telescope dynamics, atmospheric and enclosure seeing, and residual collimation error which add in quadrature with the optical contribution. These results are in surprisingly close agreement with predictions based on profilometry of the secondary mirror, lending credence to the supposition that the secondary is the dominant source of the observed optical degradation. Alleviating this problem should reduce the achieved FWHM in median seeing by about 0.2'', and would allow us to take full advantage of superb conditions when they arise. -- Alan Diercks Mail address while in Washington: Office: (206) 543-9373 University of Washington Lab: (206) 616-2960 Dept. of Astronomy Fax: (206) 685-0403 Box 351580 Seattle, WA 98195-1580 APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 22 in the apo35-general archive. You can find APO the archive on http://astro.princeton.edu:82/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO