I know whenever there is a movie being made that is an adaptation, the source material is the first thing that fans looks at. There are some people, though, who believe the source material does not matter, but I think it does. Without the source material, the movie wouldn't even be made, so lack of respect for the source material usually means a bad movie. Two examples of this are
The Last Airbender and
Dragonball: Evolution
As a child I loved watching
Avatar: The Last Airbender, it was one of my favorite shows of all time. I was seriously in love with the show, and when I first found out that there was a film, I was so happy. I never got a chance to see it in theater, thought I heard rumors of it being a crappy movie, I never believed them. Then Nickelodeon aired the film. Again, I didn't have a chance to watch it, but my best friend who loved the cartoon more then I did watched it. She said it sucked, she said it wasn't the same as the show. The film currently has a 4.4/10 on IMDb and a 6% on Rotten Tomatoes. Normally RT and IMDb do not matter to me, but when fans of the series are saying that a film is pretty much crap, then it really is crap.
Dragonball: Evolution is another example of a movie butchering its source material. I was never a fan of the Dragonball series, but when CinemaSins brings in the source material for the sins, it must really be such a hated film that CinemaSins is willing to but sins to what the fans found different. The "extra" sins were not just looks changes, it took out characters such as Krillin (as shown in CinemaSins for
Dragonball: Evolution) and completely changing characters. This film was a flop because it didn't respect the source material, the same reason
The Last Airbender was a flop (besides M. Night Shyamalan).
Films need to respect the source material, filmmakers need to understand that the source material is there for a reason. Look at
X-Men: The Last Stand and
X-Men Origins: Wolverine compared to
X2: X-Men United and
X-Men: Days of Future Past.
I have listed the two best and the two worst X-Men films. What makes the good films good and the bad films bad is quite obvious, and that is respect to the source material. The only big change DOFP made with the storyline was who they sent back, and with a good reason. As stated in multiple interviews, there was no way that they could sent Kitty Pryde back in time since she wasn't even born in the 70s.
X2 was such a great film because they took the main storyline from
God Loves, Man Kills, changed a few things, and made themselves a damn good film.
The Last Stand was a bad film because they butchered the
Dark Phoenix storyline, especially by killing off Cyclops. I understand the actor had another movie to film, but why didn't Fox just push back
The Last Stand? As for
Origins, I have one thing to say: Deadpool.
This
is not Deadpool. Not even close.
This
is Deadpool. Not some naked, mouthless, Deadpool knockoff. Literally,
X-Men Origins: Wolverine would've been a hell of a lot better if they got Deadpool right.
Now I'm not saying that films need to follow the source material perfectly, not at all. I'm just saying they need to respect the material, for book adaptations that means following the storyline for the film. The
Harry Potter films were so successful because they followed the books. Sure,
Goblet of Fire was a bit rushed, and all the movies could've had more Quidditch, but they were still good films, because they respected the books. Even though they followed the books, they had their own good scenes. One of my favorite scenes was the Death Eaters Attack The Burrow from
Half-Blood Prince. That scene was not in the book, but it was a damn good scene, and one of my alltime favorites. Another example of a film respecting the source material and being immensely successful is the first Iron Man film. The only thing that was changed about Iron Man's background was really where he made his suit, and it made sense to change it. The film takes place in the 2000s, assembly 2008, and he was captured in Afghanistan instead of Vietnam. But why would Iron Man be captured in Vietnam in 2008? America wasn't at war with Vietnam like they were Afghanistan. It made sense to change it. Another example is changing Peter Parker's parents from working with SHIELD to working with Oscorp because Sony can't use SHIELD.
So all in all, I think that if a film, especially a comic book or novel adaptation, they need to respect the source material.