This incredibly realistic lens aberration simulation was made with a motion-tracked camera and the recently introduced Ray Portal BSDF node, transporting rays that enter another location in the scene, unleashing many opportunities for creating stunning visual effects and other rendering tricks.
In the following tweet, Hans Chiu shared a quick breakdown of the technique, explaining that for similarly utilizing Ray Portal, you need to calculate how the light would pass through a lens if it has basic aberrations including spherical, coma, field curvature, distortion, and astigmatism, then assign the resultant ray position and direction to the node.
