The first two photographs in this collection were shot from exactly the same spot. The only difference was the lens.
The first image was made with a wider lens. The second image was made with a longer (telescopic lens).
In the second image you can see that the barn in the foreground and the barn in the background appear to be closer together. That is, they appear to be "compressed" together, hence the term "telescopic compression".
Use of a long (telescopic) lens creates this effect, and you can use it for creative purposes.
The second set of images in this collection were also taken from the same spot. The first one at 200mm focal length, and the second one at 400mm focal length. You can see how the hills appear to be "compressed" together.
© Jerry Weimar Photography