If you run a “whatIs AEwhichCameraFilmback”, it leads to a procedure in an attribute editor template named AEwhichCameraFilmbackNew that’s found in the Maya installation files. Here you can see the proc that creates the contents of the drop down menu and the different procs called to update the UI. Most likely you can extend this or implement this in a custom window. Hi there, I have actually tried that and it does not populates the list of available formats. The script - AEwhichCameraFilmbackNew, executes the option upon selecting a certain filmback option in the list while using the horizontal and vertical aperture along with the lens squeeze as the variables for it