823 823_v1 k1027

Below is a plot of the transmission of this filter when used at telescopes with differing focal ratios and central obscurations; the KPNO 4m (f/3.1) and the CTIO 4m (f/2.9). At the KPNO 4m the properties of this filter are: CWL=8170A, FWHM=71A, PEAK TRANSMISSION=91.5%.