There are still the dark corners directing the eye to the center that is so prized by vignettophiles, but there is also a composition of the whole frame.
How much difference will another 14 degrees make?
All except two of these are the entire negative, and those two are still wider than the 20mm.
The entire Sunroom, from just above my head. The camera looks pretty high up, but I could reach it without extending my arm. Some photons make it to the edges, but mostly just the highlights.
It's no trouble exposing the edge if it's bright enough. Another thing illustrated here is how exposure and resolution are degraded because, from the edge, the pinhole appears to be a rather flat ellipse, further reducing its area, and flirting with serious diffraction. I've known about this forever, but it's still kind of a shock to see the actual difference diagramed like this.
To fill the frame with a close-up, you have to get really close. There was barely room to get my finger between the camera and the squash to open the shutter.

