Katy Perry: My new film Part Of Me is warts and all - even my acne's in 3D
The singer says she deliberately left in footage of herself with no make-up and looking rundown because she wants to show that no one's perfect.
'I kept a lot of those scenes in where I'm not looking all done up and looking pretty exhausted,' says Katy, 27.
'And my acne is in 3D, which is not exciting!
'I think it's time to break down the wall of fakeness regarding Hollywood because it's not realistic.'
Ex-husband Russell Brand, 37, famously Tweeted an unflattering picture of Katy in bed with no make-up during their marriage.
'At the end of the day, I'm a pretty plain Jane when I go to bed and wake up,' Katy tells The Sun.
'I'm just a simple girl who had a dream and basically hustled the whole way here.'
Katy's 3D movie, which follows her California Dreams tour and tracks the breakdown of her 14-month marriage, is at cinemas now.