Low-S/N quiescent galaxy (Plate-MJD-Fiber 497-51989-573): PCA and VAE reconstructions of the Na 5896 absorption line (left) and N II 6550/6585 and Hα emission lines (right). The median S/N of the spectrum is 12 in the left panel and 18 in the right panel. Even at low S/N, both reconstructions find the Na absorption, Hα, and N II emission with only two components. The VAE still provides a better reconstruction compared to PCA with the same number of parameters, although the differences are less significant at low S/N.