The drift scan camera ( DSC ) Chip: Gain of the chip measured 2.5 e/ADU Spurious charge problem resolved. There was a problem with the DSC chip/electronics found earlier this year in that it had large amounts of "dark current" distributed unevenly on the chip. This "spurious charge" was reduced by about a factor of 9 during a recent visit by Tim McKay. It is also now distributed evenly across the chip. Hardware: Observers should be aware, that while the shutter is capable of moving quickly (20 ms minimum shutter time), it is an iris diaphram design which means that for short exposures, the center of the frame will see the shutter open longer than the edges. Tim Mckay says that for photometry one would want shutter times of at least 10 to 20 seconds to make this effect negligible. Over the course of the next few months a filter wheel mechanism will be installed. It will consist of two overlapping 6 position wheels, machined to hold 3" x 3" filters. One of the wheels will probably be dedicated to the SDSS filter set, leaving 5 positions ( not including the open position ) on the other wheel for observers filters. Computers: There are still frequent hangs of the VME crate, requiring someone on site to reset it. Software: Bernedette Rodgers has written a new interface between the DSC and the mc/tcc which provides proper telescope information to the image headers. Documentation: All DSC users are encouraged to look over the DSC home page and APO primer for details on using the DSC ( http://tycho.apo.nmsu.edu/site/dsc/dop.home.html ). Dan Long APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 6 in the apo35-dsc archive. You can find APO the archive in /u/strauss/apo/mailer/apo35-dsc on astro.princeton.edu APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-dsc@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO