Is ghosting a significant issue with any DEIMOS gratings?
Yes. Due to the large acceptance angle of the DEIMOS camera, all gratings may produce zeroth-order ghosts at some grating tilts. The 830G and 900ZD gratings are particularly prone to this at typical grating angles. These gratings are certainly usable with slitmasks, but observers using these gratings should be prepared for ghosts in their data. Please read the notes on ghosting with the 900ZD grating and heed the advice on how to acquire calibrations with the 830G and 900ZD gratings.
