Sometimes you wanna have that specific POV of someone looking through a peephole. I guess the easiest way to shoot this is by sticking your camera through a peephole.
Dave from Knoptop shares how he converted a $7 200 degrees door peephole and a PVC reducer into a wide angle lens. The vignetting is pretty strong so I am not sure it is usable as a “real” fisheye, but the effect is still pretty cool for $7.
If you like this kind of stuff, make sure to subscribe to Knoptop, they definitely know how to have fun with a camera.