I'm working through Mark Spencers Mastering Motion's Camera at the moment, which is exceptionally good!!!! but have come up against an interesting problem. I have several layers in my project which I want to be able to view from the top view. I've deselected all layers and have hit F to view everything. Unfortunately, I can't see all my layers. The items from the content library are visible as a straight white line but the four text layers are invisible. What is happening here? I have checked the the timeline marker is sitting on top of all layers.
Some objects from top, bottom, left and right views will just disappear, especially if they're lined up right on the grid.
You're better off using Perspective (it doesn't have any affect on the Active camera view which is what gets rendered.) In perspective view, you can rotate the scene to very close to top, bottom, etc. (with the "Orbit Camera" control [middle 3D View Tool icon top right of the canvas]) ... but with enough of an angle to be able to determine where your objects are. (Also, before moving around in perspective view -- select a group or object that you want to focus on -- if you select a camera or light you'll "go wide" of your view...) [Double clicking on any of the 3D View Tool controls will reset the scene.]