In my opinion it's always best to see films first and then read the
books as then you'll appreciate both. If you read the books first you'll pick apart the films until you can't stand them.
Pax Z-W, but I must vehemently, oh yes! and most strenuously disagree! 😱
Depth of character development in the written story
almost always exceeds character development (CD) in a movie (unless the movie was directed by Ingmar Bergman or Martin Scorsese 🙄) which for that reason alone (there are others) it is preferable to read the book first.
The few times I watched a movie before reading the book (and that only occurred because I didn't know the book existed) I was always struck, upon reading the book, how much depth of character was lost in the dramatization. And quite often it is not possible to develop a character to the extent that the author did in the book.
Now, the assumption I'm making is that the writer and director (and studio) are making a good faith attempt to be true to the author's story and characters in the first place... (casting malevolent looks and the
Evil Eye toward the entire
Rings of Power trainwreck.)
The movies I watched before reading the books:
The Lord of the Flies ( 1963) ...novel of the same name by William Golding
Movie was true to the book, very good character development but the CD in the book was better still.
To Kill a Mockingbird (w/ Gregory Peck) ...novel by Harper Lee...my opinion is same as it was for Lord of the Flies
Pride and Prejudice (BBC 6 part series with Colin Firth and Jennifer Ehle) .... novel by Jane Austen.
Movie exceptionally well done, character development comes close to the book. I still watch the movie, but more for the stunning depth of acting than for the story per se, but I prefer the book.
The Godfather .... novel by Mario Puzo.... Ahhh, here we have an exception.... to put it bluntly Mario Puzo can't do character development. Period. Full stop.
Coppola performed miracles in making Puzo's characters fully and deeply 3 dimensional.
This next one is a similar situation to the aforementioned
RoP trainwwreck in that the movie has the name (and characters' names), and basic story outline (really minimal) but otherwise bears little resemblance to the book and so, in retrospect, I'd have to say CD suffered exceedingly.
Memento Mori.... novel of the same name by Muriel Spark.
I enjoyed the movie, so I read the book. All I can say is that I never watched the movie again, but have re-read the book at least a dozen times.
Now to use PJ's LOTR movies as an example.....
I can't tell you how many times I've heard/read people saying that
Boromir was evil, or just a power hungry jerk, or that
Denethor was another jerk and thoroughly unlikable, or that
Faramir was weak.
Then you read the books and learn how wrong, oh how so very wrong, those assessments are.
Yet those first impressions still stick in your mind, because that is the way our minds work. . (You've heard it said: "You only get one chance to make a first impression.")
It is why it easier to get people to embrace a new idea even if they think it is wrong , than it is to get them to change their mind about an idea or belief that they already hold,
even when that idea or "fact" is proven to them to be objectively false.
So, I would only encourage someone to watch PJ's LOTR or even the abominable RoP
first, if they never intend to read the books later.
I would say that concerning any movie based on a book.
Book first (if you know the book exists) then movie. If movie first, don't bother with the book.
(And I do know there are going to be strident cries of disagreement about this 😉)