Focal Lengths and Different Viewpoints

I visited a nearby lawn cemetery in order to experiment with perspective. I chose this particular location as I thought the rows of gravestones would clearly show the effect of depth-compression in the scene.

55mm, f/5.6, 1/320, ISO 800

I was hand-holding the camera at this point, and needed to bump up the ISO to get a sufficient shutter speed. In the image you can clearly see the entire row of gravestones contained within the frame, and a white tree trunk at the far left.

18mm, f/4, 1/1600, ISO 800

I then changed to a wider focal length, and physically moved forward until the scene in the viewfinder approximated the first image. Here, you can still see the entire row of gravestones, with the white tree at the far end. The perspective however has changed in two ways:

Elements within the scene: The gaps between each stone now seems much wider, as does the gap between this row of stones, and the row behind. The distance between the closest gravestone and the tree at the end of the row seems much further in the second image.

The viewer and the scene: As the viewer, I seem to be further away from everything in the second image. In the first image, objects that appear only a few steps away, seem to be far into the distance in the second. In the nearest gravestones you can see that they appear wider in this image than the first.

The longer focal length has 'compressed' all of the objects in the first image. Everything appears bunched together, and altogether it looks like a packed landscape. This focal length would be useful if you wanted a view to look busy, or full.

The wider focal length in the second image has done the opposite, creating lots of space between the individual elements in the scene. It appears to be a vast landscape, and this focal length would be useful if you wanted to create the impression of space, and distance.