The computation of interstellar extinction in photoionized nebulae Christophe Morisset, Romano L. M. Corradi, Jorge García-Rojas, Antonio Mampaso, David Jones, Karen B. Kwitter, Laura Magrini and Eva Villaver A&A, 674 (2023) L6 Published online: 09 June 2023 DOI: 10.1051/0004-6361/202346296