09-05-2016, 01:13 AM
Take the equiv lenses - set to 2m - both put on a tripod that isn't moved, of course.
For the arguments sake - let's take a portrait.
How could the nose, the eyes, the ears be possibly any different?
Because of the same distance, the angle to those points is exactly the same.
If the angle is the same, the compression is the same.
Compression is about focus distance.
If you stay with the same format, you have a different compression for an ultra-wide, wide, std, tele, super-tele ... because they are used at different focus distances (for that head portrait). Different focus distances = different angles.
q.e.d.