Spectral profile of a line near the centre of the J band with the 250 mas pixel scale. Left: as it was in SINFONI. Right: as it is in ERIS, after replacement of the mirrors and gratings. The profiles have been normalised to the same total flux, showing that not only is the resolution improved, but also the sensitivity to unresolved lines. This effect is more significant at shorter wavelengths and smaller pixel scales.