[Brightcolours]

There is some disambiguation.

No, there is not. Just some misunderstanding on your part  (and the wonky photozone forum post editor is driving me crazy here!)

If to be precise, according to Wiki, field of view is "the extent of the observable world that is seen at any given moment", so at 1:1 it doesn't differ between the lenses

It very much differs between lenses. FOV is not about the size of the subject (which does change with subject distance), but about the angle of the "cone" you capture (the FOV does NOT change with your distance to the subject (well... it kinda does with most lenses, but that is not what I am trying to explain here)).

 

Imagine you have a VW Beetle you want to photograph, in a street. You can photograph it with a 35mm lens, or you can photograph it with a 200mm lens. If you let the VW Beetle be the same size in each image (so the same magnification...) you can imagine that what else you see in the image is different in each photo. The 35mm lens image will show much more in the background, or a much wider Field Of View. The 200mm lens will show a much more narrow FOV. The perspective will be different in each image too, because you had to change your view point to get the VW Beetle to fill the same amount of the image with the different focal lengths.

 

Now imagine you want to photograph a beetle on a leaf in a park. You can do this with a 35mm lens, or a 200mm lens. The same applies as with the VW Beetle above... If you make photos with both lenses, with the beetle (the focal plane) at 1:1 projection size, the background will still be very different between the two images. The 200mm lens will show a much more narrow Field Of View, the 35mm image will have a much wider FOV. It does not matter if one shoots 1:1, 1:2, 1:50 or 1:500, The FOV will be very different between a 35mm lens and a 200mm lens.

(like on this example from dpreview);

Imagine that you have a window in your house, with a view of a mountain range. One day someone parks a large truck right in front of that window! Did the mountain range disappear? No, it just got blocked from view by a truck. 

That is what this "example" shows. It shows a ruler blocking the view. It does NOT show anything about FOV, though.

FL only defines the distance, at which it is achieved; so angular extent, or angle of view will differ between lenses with different FL.

In fact, field of view and angle of view are synonymous.

Yes, FOV usually is expressed as angular size, but sometimes it is more convenient to express it in other metrics (like this example).

Don't let their imprecise nomenclature and explanation confuse you.

IMO this difference is the key to bypass FL.


A.