Fig. 1
Setup of the observations in a top view. BS1: dichroic, splitting into NIR (>800 nm) and VIS light. BS2: dichroic with its edge at 450 nm, splitting between the Göttingen FPI and the imaging channels. BS3: achromatic, 50/50. The two imaging channels in Ca ii H and blue continuum used BB prefilters in front of the respective CCD cameras.
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