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Flat/Arc Exposure Times


GCAL configurations and Exposure Times for GMOS calibrations: Quartz Halogen flats and CuAr arcs



Note the following:

  • Exposure times for GCAL GMOS calibrations are set automatically in the OT ('SmartGCals'). Please use the exposure times provided in the OT for flats and arcs. 
  • If you are choosing to use a manual arc or flat, you can first set up a (Smart-) "Arc" or "Flat" to find the automatically-set exposure times. Then click the "Configure Manually" button in the corresponding 'Sequence Component'.
  • For manual flats, please use GCALlamp=Quartz-Halogen, GCALdiffuser=VISIBLE. For manual arcs, please choose the CuAr arc and GCALdiffuser=VISIBLE.
  • The GMOS-N and GMOS-S detector controllers only support integer exposure times.
  • The GMOS gratings (with the exception of the R150) have significant scattered light, since the QH lamps are very red and arc lamps have very strong red lines.