My five star rating system has evolved over time and I now have a loose interpretation of each to ensure there is some consistency.
5 stars: It changed my world view.
4.5 stars: It kept me totally engaged.
4 stars: I would watch it again.
3.5 stars: There are lots of good bits.
3 stars: It’s okay.
2.5 stars: Too long, too confusing, too something.
2 stars: Not really sure what it was about.
1.5 stars: Something in it really annoyed me.
1 star: I have no idea why this film got made.
0.5 stars: I want that two hours of my life back.
Oh and black and white cinematography adds half a star.