[fvgvkujdfbllo]

The way I understand is that it is not FOV but zoom level. If you look through a camera with 50mm lens, the subject and background should appear same size as when viewed with naked eyes. Doesn’t matter if it is full frame or crop sensor.

[_aavaa_]

Relative size of subject and background is cause by distance to them, not focal length.

[tveyben]

Also called ‘perspective’ and the only way to change it is to move the position of the camera

It does not matter if you crop an image taken with a 50mm lens to get the same area of the motive as taken with a 300mm lens from the same ‘standpoint’ - there will be no difference between foreground and background (except for grain and noise - but that’s another story… ;-)

You have to move the camera to change that.

This is often seen in movies (those shot on real film) as opposed to on video as zoom lenses are often used without moving the camera, film based often use a dolly to move the camera. The effect of combining zoom and camera movement to keep the same crop of the foreground while having a dramatic effect of the background quickly getting larger/closer (or vice versa) is really effective - also in illustrating this concept.

In my early life (before taking the education as a photographer) I was really liking wide angles as it brought ‘life’ in to a lot of pictures. Wide as in 24 mm for my 35mm camera (Nikon F2, from 1973 should you wonder) was a favorite, replacing my 28 mm.

Too bad full frame digital is still so expensive. Using a 14-24 f/4 on the DX format in (Nikon D7100) just is’nt the same.

So now the iPhone is the most used camera (you know - the camera you have with you…!)

[fvgvkujdfbllo]

If you have 50mm lens, try it. It will look exactly same as if you are looking through a tube with a naked eye.

[hk__2]

Both, actually.

[_aavaa_]

It’s entirely independent of focal length.

It has to do with the ratio of the subject-camera distance to the background-camera distance.

As others have pointed out you prove this to yourself in one of two ways:

1. Frame with telephoto, then shoot with a wide angle lens and digitally zoom in photo.

2. Frame with wide angle and then shoot a panorama with the telephone and stich.

2 is significantly harder if you are close to the subject.

[rozab]

Well, no. This article has some clarifications: https://petapixel.com/is-lens-compression-fact-or-fiction/