Guide to CISCO/OHS spectroscopy exposure times
The following table lists the point-source saturation magnitudes for various exposure times with the grisms, with a 1 arcseond slit under good seeing conditions. Also listed are the times taken to achieve background limited performance (BLIP) with CISCO for a 1'' slit (the time is directly proportional to the slit width). The range indicates the variation in background over the grism's wavelength range, with BLIP being achieved at the longest wavelengths first.
With OHS, background limited operation is achieved in about 1000 seconds with a 1'' slit, and about 2000 seconds with a 0.5'' slit. If shorter exposures are used, the sensitivity will be decreased.