ext defaults to 'flux' even if called as None
ext defaults to 'flux' even if called as None

bretthandrews/marvin,sdss/marvin,bretthandrews/marvin,albireox/marvin,bretthandrews/marvin,albireox/marvin,bretthandrews/marvin,sdss/marvin,albireox/marvin,albireox/marvin,sdss/marvin,sdss/marvin