Detector image plane of a single exposure on the Cat’s Eye Nebula (NGC 6543) showing three kinds of spectral contamination from a bright emission line (Sulfur IV forbidden line at λ = 10.5115 µm). The first kind is between dispersed slices, occurring on the right half of the detector. The second kind is between the wavelengths dispersed on the right half of the detector and the slices on the left half of the detector. The third kind of contamination is visible in the detector rows under those impacted by the bright emission line, specifically in the background. This one is lower due to the pull-up/pull-down effect linked to the bright emission line.