SKY RATES
(last measured 21 Oct 2000)

To aid in planning observations, we've measured sky rates with the Mosaic II for moonless sky. Note that these are given in electrons/sec and are the average for all 8 CCDs. Given that several of the CCDs have low full wells (above), one must be especially careful with the I filter to not limit the dynamic range of the observations (e.g., a 20 min exposure only leaves you a usable range of 10000 counts).