* use ecam in ui
* needs reboot
* use in modeld
* typo
* effective FL is longer in center
* normalize zoom by focal dist
* read param before init
* make 2x as wide
* review comments
* more explicit
* fix camera offset
Co-authored-by: ZwX1616 <zwx1616@gmail.com>
old-commit-hash: 1fc7bcca43e9ef75d95ae8689e3b1cd8c4f8041e