Currently because MegaPrime and DECam use multi-extension FITS files to store data for all detectors in a single file, we need to have a special ingest task. It's easy to miss this and end up ingesting a single detector.

Investigate an alternative scheme where a file header is read from FITS as now, the instrument is determined and then a method on the instrument class can return additional information (such as headers indexed by HDU) if needed.