It is interesting to compare the mediums of fiction writing and cinema with regard to world creation, especially in the case of fantasy and science fiction. In the written medium, the writer has to painstaking describe everything. In the case of cinema, it is possible to skirt these descriptions by using elaborate stage sets or CGI. In the written medium, it is not practical to expend too many words on description, so the writer must depend upon the imagination or acquaintance of the reader with a comparable reality. However this is surely unequal, and this inequality will mean that, to a greater extent than in cinema, the experience of one reader to the work of fiction will be widely different to that of another. This is not true only for fantasy and science fiction, but in general. One reader will imagine a character in a different way to that of another. But still I think it is especially true, when the world in which the story takes place differs from that of the reader. On the other hand, a novelist who is writing about his contemporary reality, which he/she assumes that the reader already knows, is unlikely to expend too many words about describing it. This means that when we read books that were set in an earlier era, we have to be able to fill in the details of their reality from our knowledge of the era. Here it will have been helpful to have seen films, because someone else has done the research about those eras, and have been able to depict them more or less accurately. But imagine if I am reading a novel set in the early 19th century and have not seen any of those films, or have watched them inattentively, my mind might create a backdrop that confuses images from the 17th or early 20th century with the time period of the novel. In that sense, a science fiction or fantasy writer has the advantage of not being able to assume that the reader knows the world that he is describing, and must more carefully describe it.
I think that, in any case, the keyword is atmosphere. The description must be able to create the atmosphere that is suitable to the story. The effort that a writer spends on description is especially aimed towards that. I must be able to feel the atmosphere of the backdrop even if I cannot fully visualize it.
It will be interesting to see what Villeneuve creates in the new version of Dune that is due later this year.
