[TacticalCoder]

> I have difficulty understanding what the transformed image is equivalent to.

As a non-photographer with zero knowledge about photography, the fixed image, with straight lines, feels much more natural to me.

I'd say it reminds me of 3D games like, say, 3D game simulators?

Are 3D games not reproducing lens deformation more or less correct from a "physics" point of view? I happen to be on vacation atm in an apartment on the beach on the ninth floor with a clear view: what I see is much closer to the "corrected" (not my word but TFA's author's one) version than to the other one.

[wlesieutre]

The author is saying "wide angle lens" but means what people would conventionally call a "fish eye lens." Normally when someone says wide angle, it's still assumed to be a rectilinear image projection, same as what you get with 3D game rendering. And if you're talking about a curvy fisheye projection, you specify that.

The iPhone's ultrawide lens is a good example of a rectilinear projection with lots of example photos available.

It can produce weird feeling images with stuff at the edges looking stretched out, and parallel lines being at significant angles to each other, but it does not make straight lines curved like the effect that the author is removing.

Example ultrawide photo with straight lines from reddit https://www.reddit.com/r/iPhoneography/comments/ena7s5/bosto...