Illustration of the x − λ and y − λ shifts in a slice of a SPICE spectral cube, with the intensity raster shown in the C III 977 Å line. Panels (b), (c), and (d) show zoomed-in slices (corresponding to the red square in panel (a)) where the x − y shift is apparent as a slight translation of the same features when scanning through consecutive wavelengths. Please see the online for an illustration of this effect.