It's amazing how wide the perspective is from my Sigma 15mm fisheye lens.
Take a look at the display cases with the flags in this photograph of the rotunda inside the Michigan State Capitol in Lansing:
The flags are positioned just off the floor around the rotunda.
While preparing to capture of picture of the inner dome, I laid down in the center of the floor. Here's that image:
Note that the flag cases are visible in the edges of the frame. The perspective is super wide.
Last week, I was taking pictures inside Overture Hall in Madison, Wisconsin. My host was sitting a few seats to my right while I was capturing photographs of the theater from the balcony. She was surprised when I asked if she would mind moving back a bit as she was still in the frame!