Converts retinaldehyde to retinoic acid (PubMed:8797830). Recognizes as substrates free retinal and cellular retinol-binding protein-bound retinal (By similarity). Lacks activity with benzaldehyde, acetaldehyde and octanal (PubMed:8797830). Displays complete lack of activity with citral (By similarity). H2O + NAD(+) + retinal = 2 H(+) + NADH + retinoate Cofactor metabolism; retinol metabolism. Homotetramer. Belongs to the aldehyde dehydrogenase family.