Smaller the focus length, the more the distortion, especially around the edges of the picture. Also, the proportion difference of objects close to the camera to objects far away from the camera will be greater, which results in a big nose.

jerry-jiao

@Sainan could you explain the distortion a little bit more in depth? I'm a little confused as to why the distortion occurs around the edges of the picture as the focus length gets smaller.

briana-jin-zhang

@jerry-jiao
This video gives you an intuition behind the distortion: https://www.youtube.com/watch?v=tod2qZnKZEQ&t=468s

I think a somewhat mathematical explanation might be that for example, let's assume the buildings are all of the same depth. The problem is that the distance to the camera in terms of rays will still be varying (think of the side of a right triangle being the depth, and the "distance" to the pinhole being the hypotenuse). I'm not sure if this is correct though, hopefully a TA can clarify.

Smaller the focus length, the more the distortion, especially around the edges of the picture. Also, the proportion difference of objects close to the camera to objects far away from the camera will be greater, which results in a big nose.

@Sainan could you explain the distortion a little bit more in depth? I'm a little confused as to why the distortion occurs around the edges of the picture as the focus length gets smaller.

@jerry-jiao This video gives you an intuition behind the distortion: https://www.youtube.com/watch?v=tod2qZnKZEQ&t=468s

I think a somewhat mathematical explanation might be that for example, let's assume the buildings are all of the same depth. The problem is that the distance to the camera in terms of rays will still be varying (think of the side of a right triangle being the depth, and the "distance" to the pinhole being the hypotenuse). I'm not sure if this is correct though, hopefully a TA can clarify.