my point was really in the sense that for the last few books (Order of the Phoenix and on), they were released after the first few movies had already been released. And that's when a large majority of people started reading the series.
obviously if you read all the books available before the movies, you would have formed your own views of the characters - but having a unique situation where movies were being released before the book series was complete morphed my views on the characters. How could it not?
I do agree that Tonks probably wasn't the best example - She didn't match what i envisioned her to be. BUT, when i read DH, i couldn't help but picture her as the actress in my mind after seeing OOTP, even though i had already formed my own view of her when reading OOTP. It's simple visual association.
__________________
|