Increase cameras Field of View

I would like to take images in-game with a fish-eye projection. After reading a lot of posts, I think it is clear I need to create a post processing effect to simulate distortion according to intrinsics and extrinsics matrices (both of them known).
The issue here is with the maximum field of view that unreal allows to set. Only perspective projection up to 170º is allowed. I am aware that pin-hole cameras have the 180º limit, but I was wondering if there is a way to go low level in Unreal to increase the field of view of the cameras.