93% of Oscar voters are white, 76% are male
The question of who votes for the Oscar nominations and awards used to be shrouded in secrecy, but the Academy of Motion Picture Arts and Sciences has recently opened up about the process.
This is a rundown of who gets a say, how they cast their ballots and how the prizes to be handed out on Sunday night are awarded:
The Academy recently told AFP that its 6,000-plus voting members are 93 percent white and 76 percent male. The average age is 63.
A Los Angeles Times investigation in 2012 found that while almost half of voting members had appeared on screen in the previous two years, hundreds hadn't worked on a movie in decades.
"Some are people who have left the movie business entirely but continue to vote on the Oscars -- including a nun, a bookstore owner and a retired Peace Corps recruiter," it reported.
The board of governors has announced action to double the number of female and ethnic minority members by 2020 in response to an outcry over the lack of diversity among its ranks.
For most categories, nominees are chosen by the members of the corresponding branch -- so actors nominate actors, film editors nominate film editors, and so on.
Certain categories such as best foreign language film and best animated feature film have special voting committees.
All voting members are eligible to select the best picture nominees.
Voting for the winners
On February 12, the Academy activated the website that allows members to vote online for the winners, having already put paper ballots in the post. Members had until 5:00 pm (0100 GMT) on February 23 -- Tuesday -- to have their say.
Members are asked to rank the eight nominees for best picture, with ballots subject to a complex counting method that involves eliminating films with the least first place votes and redistributing their votes.
Voters choose one winner in a much more straightforward ballot for each of the other 23 categories.
Joining the Academy
The Academy is an extraordinarily exclusive club.
A candidate has to be put forward by two members who believe he or she has "demonstrated exceptional achievement in the field of theatrical motion pictures."
They can also be considered if they have landed an Oscar nomination.
But that's only the beginning of the selection process, which also requires the vetting of potential members by branch committees, which can recommend them for approval by the board of governors.
Beginning later this year -- not affecting votes for the 2016 Oscars -- each new member's voting status will last just 10 years, and be renewed only if they have been active in movies during that time.