freyfaxi62 posted at 5:57AM Mon, 28 October 2019 - #4368517

Using the "file-import -background picture" option ..could someone please tell me what the max size should be ?

From the Reference Manual:

Preview Dimensions

Selecting Preview Dimensions brings up the Preview Dimensions dialog. Here you can specify your desired height and width (in pixels) of the scene preview window. Clicking the Match Background button forces the Document window to match the dimensions of an imported background image or movie. Clicking the Match Production Aspect button sets the scene preview window size to the currently selected Production Frame aspect. This button is only active when the Production Frame feature is enabled (see “Production Frame” on page 123). Clearing a checkbox disables the specified option.