Simulated Scene Import Questions

When importing a picture as a simulated scene, I cannot achieve a full view of the picture in the scene window no matter what the original resolution of the pic is or what I set as the HAoV for the import. Camera height and angle also have no effect. If I use the default HAoV of 90 degrees, the pic comes in as framed on all sides by a wide black border and only about one quarter of the top left corner of it is visible as the scene. If I set the HAoV to 120 degrees or higher, I get rid of the excess black space on the left, but can only see the top of the scene in the window. If I use 70 degrees or less HAoV, the black area increases and the amount of scene shown decreases.

The source pics are from a mobile phone taken in landscape orientation. Do I need to crop the pictures to some arbitrary size prior to importing them? Do they need to be a certain ratio of H x W to import and completely fill the scene window? I think I've looked through the documentation and these online discussions in depth but not seen anything about this mentioned.