Vertigo Dolly Zoom Camera Effect (Patreon)

Wanted to figure out how to set this up via expressions after seeing Blake Kathryn's animations https://twitter.com/blakekathryn/status/1322193983401910273

Ended up with something like this in the camera's 'focal' lens mm parameter:

15 *(atan2( (ch("resx")/ch("resy"))*abs(ch("tz")), 25 ))

See the notes and sources in the hip