Harry Potter fans would likely agree that J.K. Rowling's beloved novels are far more in depth than the eight movies were able to be. That's just the nature of adaptations. But that doesn't mean the films weren't able to give us information about the characters that wasn't previously in the book. Such was the case for the Black family tree. The book doesn't go into a lot of detail about the names and branches of Sirius' family tree, so when it came to adapting the setting for the movie, the filmmakers had to go to the source herself for more information, and they got it.
When speaking to David Heyman on the set of Fantastic Beasts and Where to Find Them, he spoke a bit about how well J.K. Rowling knows her own world. That led into him mentioning that when it came to the Black family tree, they didn't have enough details to create the tapestry featured in Harry Potter and the Order of the Phoenix, so they got in touch with her...
Let's pause for a second and envy the filmmakers for being able to email J.K. Rowling with a question about the Harry Potter universe, and receive an in-depth response just 30 minutes later. Honestly.
Also, six generations of Black family history!
It's not as though J.K. Rowling hasn't demonstrated time and again that she has all the answers. In fact, she probably has more answers than we have questions about the characters and history of her world. Still, it's a great little turn to know the movie was able to deliver such accuracy with the Black Family tree. They actually went above and beyond in the way they created it for Order of the Phoenix. In the book, the family tree is described as a tapestry, spanning the length of the wall. However in the movie, it looks like it covers at least three walls of the room, and there are most definitely names and pictures for each member.
Considering it's all just background decoration, apart from the parts that Sirius shows Harry, they could've probably gotten away with fudging the details and leaving it at that. It's a mark of their efforts for accuracy that they reached out to Rowling, and it's a mark of J.K. Rowling's dedication to her material, and thoroughness that she was able to provide them with six generations of Black family history.
Of course, David Yates likely had no shortage of input from J.K. Rowling on Fantastic Beasts, as the author wrote the screenplay for the film. Not only are they not relying on novels as the source material for Fantastic Beasts, but they no longer have to stress about making movies based on a series that hasn't been completed yet, which was the case when David Yates was directing Harry Potter and the Order of the Phoenix. It's a whole different ball game this time around, and we can't wait to see what information about the magical world is revealed when Fantastic Beasts hits theaters November 18, 2016.