Pick curves-on-surface, locators, image planes, objects with the same shaders, templated objects, and objects from within a group.
The image plane floats behind other types of geometry and always remains flat to the computer screen like a background.
Picked image planes display in modeling windows with a highlight around the border.
In the SBD window, picked image planes display with a highlighted border, below their camera.
You can pick image planes in the SBD window using any of these object picking modes:
Pick all surfaces using the same shader
All surfaces to which that shader has been assigned are automatically picked.
You can pick selection handles (and their target objects) with the Pick > Object tool. This tool only picks selection handles, allowing you to draw a pick box around lots of objects and only pick the selection handles.