Both camera frustum culling and fog interpret the edges of the screen as being closer to the camera

[jkstrawn]

You can see from the gif that as I rotate the camera, fog and culling are not consistent at the same points on the terrain. The fog is lighter at the edges then gets denser at the center, and the geometry is culled as it gets to the center. It’s like they are both interpreting points at the center of the screen to be further away than at the edge, even though it’s distance is the same. Is there something that can be done to correct it or do I have to write custom culling and fog?