Just some additional comments on DIS - Regarding the uneven focus across the DIS red chip, Gene Magnier noticed it was there in some fields and not in others, suggesting something moving around inside the instrument, perhaps the imaging mirror. I checked the imaging mirror for the red chip while I was in there changing the gratings and I couldn't get it to budge. It might be worth having someone elso look at it, though. Better to really rule out the mirror before opening up the camera. Also, we're still getting a slightly bimodal distribution of pixel counts in the red chip bias. It's quite variable. I think this needs to be looked at. I'm concerned that the red chip is going to poop out on us one of these nights. Regarding the medium resolution gratings. I did two swaps this week. Each time it took 2 hours (1/2 hour to physically change the gratings and 1.5 hours to redetermine the grating zero points). I expect this to go down with practice, but don't see it taking any less than 1 hour. It's not the sort of thing you'd want us to rush. It'd be really sad if a grating was dropped because someone was in a hurry to get on the sky. So, it really is important to notify us at least a day in advance (about 1/3 of the time I get filter requests a few hours before sunset) because the observing specialist will need to come in an hour or two early that afternoon to swap the gratings. I'm sorry to hear that some observers didn't get the gratings they requested. So far, this week's UW08 run is the first request I've had to use the medium resolution gratings for science. So, if users have been requesting the medium resolution gratings, the message hasn't been getting through. Send email to techstaff@galileo.apo.nmsu.edu to let us know about grating requests. - Karen APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 278 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