There is an effort underway to make the "Bright Quartz Lamps" at APO considerably brighter, hopefully at least 4-5 times brighter, by installing brighter bulbs. This will only change the Bright Quartz, not the "Dim Quartz" lamps. It is my understanding that the Dim Quartz are used by imaging folks and the Bright quartz lamps are only used for spectroscopy, for which they are not very bright at all. Obviously, this is meant to be an improvement and to noticeably shorten the time required for spectral flat-field calibrations. If you have any concerns or questions about this pending change, please bring them to my attention: rodgers@astro.washington.edu Also, since I normally use hi-res mode with DIS, it would helpful if someone could tell me a typical exposure time for flats in low-res mode, and the corresponding counts. Before a change is made, the lamps will be checked out in all (spectral) modes of DIS and GRIM and the results reported here. There should be no change to the operation of the lamps. Cheers, Bernadette APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 314 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/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