CoronaCam Overscan is a MaxScript built to overscan a Corona Camera inside 3ds Max. It lets you overscan your render in both width and height, and when you modify these parameters it automatically changes the focal length (or FOV) of the camera.
The overscan is automatic. You need only select a CoronaCam before changing the width or height value, and make sure the render setup window is closed first. For security, the script will close that window by itself. Usage follows a short path: select a CoronaCam, adjust the width and height parameters, and you're done. If you switch cameras, click refresh before using it again.
CoronaRenderer must be installed to use the script. Installation is done by dragging and dropping the file into your viewport, then adding it to a toolbar through Customize User Interface, where it appears under the "# Scripts" category. Released as v1.00, it is compatible with 3ds Max 2018 and 2021.