And one more photography link.
Back in the day when filmmakers were itching for wider and wider field of views (FOV) for their movies, it got to a point where they wanted to get so wide that the 35mm film and spherical lenses they were shooting with couldn’t hold all the horizontal imagery they wanted without cropping the image.
The solution? Literally squish the image horizontally using a special lens so it could take up more vertical space, fitting a wider image on the finite area available to them on 35mm film. They could then un-squish the footage in post using a lens with the exact opposite amount of squeeze, returning the proportions to normal. The resulting effect is a panoramic aspect ratio that has the depth of field (DoF) of a longer telephoto lens but with a wider FOV.
(Via Phil Coffman.)