Film based astrophotography has been around for decades. Because film based exposures take many hours, film based astrophotography has been loosing ground to digital astrophotography. It takes a lot of patience to capture a deep space object with film.
For a log time there was an argument in favor of film in that the resolution wos far greater than that of digital. Over the past few years, digital sensors have not only increaced in resolution but also in sensitivity. The ammoutn of noise created when taking log exposures has also been reduced.
It is now hard to make an argument for film over digital these days and the dark rooms at many obvervatories have become storage areas.