Experiment....

I took 7 pictures of a straight wall.
My stitching software has 2 positions:
Perspective & Cylinder

Here are the two different pictures placed in one frame.
It is here not allowed to put a clear line between the two pictures, so it is not so clear now, but the top-photo is: Perspective, and the bottom: Cylinder
The distance to the wall was about 75cm / 30 inch

Just an experiment....