something i shot a couple years ago with my 7artisans 7.5mm, had a reason to go edit it for another post elsewhere so there ya go, have a distorted fence
This is a area of photograph I have not gotten into but it is interesting looking at what other's do with it.
you can use a fisheye lens (not a circular) as a level ultra wise if you shoot it level with the horizon. i was just about an arms length away from a tree and i could get the whole thing in top to bottom.