Actually, special lenses like anamorphic lenses are something you don&t associate with animated films. But Pixar, for example, used various virtual simulations of real lenses and cameras in the latest part of Toy Story. This results in a look that might only be noticed by professional viewers and cameramen, but nevertheless creates a certain look that unconsciously reminds viewers of real movies and great cinema. Toy Story 4 is the first part to be produced in 2.39:1 Cinemascope format.
Split Diopter Shot in Toy Story 4
For example, Pixar uses a virtual split focus diopter to simultaneously focus on two objects at different depth levels in a specific scene, and Cooke anamorphoses to use a shallow depth of field and typical artifacts.
And already in "Inside Out" (2105) Pixar used for very special looks simulated ARRI/Zeiss Ultra Primes and Cooke S4 lenses and also in some scenes a virtual camera, which was guided manually. Disney in the remake of "The Lion King" did a similar job, where the DoP Caleb Deschanel filmed the action via a VR interface as if real camera technology was in use - including Stedicam, Dolly operators, drone pilot (for aerial shots) and focus puller.
Nerdwriter Evan Puschak explains why and how Pixar uses his virtual lenses in his latest clip.