Hi folks - I'm about to go on my first DIS observing run, so I'm trying to figure out exposure times. I've hit some snags, I've tried RTFM-ing, and now I need some help from the community of experienced users. I have some data that I borrowed from someone here at the UofC, and was going to scale things from that, but it turns out that there is some doubt as to whether or not a filter is where it should be. I have some guesses from some people on approximate exposure times, but I'd like some more guesses from more members of the community on at least one star so that I can scale the rest of the exposure times. The stars that are my targets run from 13th to 19th R magnitude, which means (via a table in Mihalas and Binney) that the V magnitudes run from about 13th to 21st. We'll be observing with the B filter on the blue side and R & I (in two exposures) on the red. (FYI: We're doing differential photometry, and we've got to do many fields in a little bit of time each night, so not saturating the chip is very important as we have no time to wait for the deferred charge to drain off.) Any sample times you can give me would be greatly appreciated! thanks VERY much, Luisa Rebull Department of Astronomy and Astrophysics University of Chicago APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 9 in the apo35-dis archive. You can find APO the archive on http://astro.princeton.edu:82/apo35-dis/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-dis@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO