I think that the pinhole model is a useful way to understand the intuition behind perspective. I was curious how this intuition can be transferred to our "normal" vision without the pinhole. Since there are presumably rays of light coming out from the object in all directions, how do we know where they "meet"? I guess I don't have a great understanding of how light works in general.

To the comment above, I think light-field may the keyword that you are looking for. Prof. Brian Wandell at Stanford has written a great book about human vision, including how light-field representation works. Prof. Gordon Wetzstein at Stanford also has lots of fantastic research projects that center around light-field imaging. Here are the links to their websites for your reference:

https://foundationsofvision.stanford.edu/ http://www.computationalimaging.org/

@ligia another cool resource for understanding how a pinhole camera works relative to the normal eye is Prof. Marc Levoy's old material which also talks about focal length and aspects of a real camera.

Instead of the pinhole, we have pupils. Just like the pinhole, the pupil only lets through small amount of light rays from the object. Without it, we would see very noisy images(not focused) all over the retina. A quick explanation can be found here on the slide 3. http://web.stanford.edu/class/cs148/pdf/class_03_virtual_world.pdf

Thanks for all the responses!

Note to all on this thread:

1. great comments

2. Don't forget to use Markdown syntax for links for convenience for readers. This is a link to this page. This is a an event simpler link to Markdown help https://www.markdownguide.org/basic-syntax/.

One interesting thing I think is how our brain adapted to the up-side-down signals on our retina after. I searched this online and found this answer pretty useful:

https://psychology.stackexchange.com/a/339

It sounds like there's a process called "perceptual adaptation" and human brain and gradually adapt to whatever image that works for it the best. So in an experiment, some people were wearing an inversion glasses, and after some adaptation, they could even ride a bike with the inversion glasses!