High-resolution “raw” corrected spectra from the same slit position as shown in Fig. 2. Panel a: IRIS data. Panel b: SPICE data. Panel c: Correction applied to the degraded IRIS data. Panel d: Correction applied to SPICE data. The last two panels are at a higher spectral resolution than the input SPICE data. The higher resolution was necessary to resolve the spectral line. This over-resolution results in some noise-induced ringing and other ripples in the SPICE data, which we resolved by returning the image to SPICE pixel scale plus a “nominal” PSF, shown in Fig. 12. Otherwise, the original IRIS line width was recovered, while the elongation and tilt of the SPICE PSF was removed.