Hello There, i was looking in the internet how to do a Fisheye effect in UE4, but i can’t find a tutorial, (Yeah, i know, there is the Eat3D video, but he don’t explain how to implement the fisheye in your camera at the end of the tutorial), so, how can i get a fisheye effect in UE4?, So, someone can help me?, i know, nothing is gonna answer and you’re going to ignore this question, but if you can help me, i will thank you! 
(Sorry for potato english in some parts, i’m Argentinian xD :P)
I have found that a good solution is to use a post process material which contains the proper parameters for such an effect. Here is one I have created which works great: Elias Wick | Fisheye.
It’s cheap to use and can easily be turned off due to the modularity from being a post process material. Let me know if you have any questions.
If you’re in for a more performance-expensive solution which can cover extreme wide-angle fisheye images up to almost 360°, Arkrias has made a nice guide about a rather easy way to build a stereographic fisheye camera in Unreal here: How to do fisheye lens in UE4? - #21 by Arkiras