RMS achieved for the west camera of the northern station during the second quarter of 2015. Shown are the RMS on the five-minute binned light curves of individual stars with >500 data points (black points) and the median relation in bins of Δm_V = 0.2 (blue line). We achieve an RMS of ~0.5% at the bright end of our magnitude range and ~2% at the faint end. Similar RMS is achieved by the other cameras.