Right now in the BingAR sample the search radius is fixed to roughly 300 yards (or the equivelant distance in Meters). Is that what you're referring to?
Right now WorldView has a fixed far clipping plain of approximately 300 yards as well. The reason was that the UI for anything beyond 300 yards would be scaled so small it wouldn't be legible. If you have a scenario where you want things drawn
in WorldView beyond this range, I'd love to have your feedback. We could make this a configurable property.
You can always add items to the ARDisplay.ARItems collection that are further than 300 yards. The WorldView won't render them but they'd show up on any OverheadMap view or in any ListBox you might also have bound to that collection.