Whats wrong with r3d files?

[Elrosthir]

Hi, I'm working with r3d 4k video in After Effects but I've noticed there's a lot of "graining" in the videos that reduce a lot it's quality, is there something wrong on how AE handles r3d videos? I can't even do a decent green screen removal with so many grain...

[Byron Cortez]

If you can upload screenshots and show us to see the same as you.

[Elrosthir]

Here, it may look fine at first but then if I try to apply keylight I can't get a good result no matter how much I change the values...