Like any Reach Game Type, the player waiting to respawn can view the game play through switching of camera views. But unlike most Game Types, the selection of camera view has everything to do with where they will spawn next and not just studying the action taking place. The current view of the Respawn Camera is the currently selected respawn location, and this mechanism can be used in interesting ways.
The Respawn Camera is found in two forms - either the Battle Buddy of the respawning player, or an Invasion Respawn Zone (usually a Hill Marker, but can also be forge objects like blocks, braces, doors, walls, crates, etc.; can be a Respawn Zone, but cannot be a Respawn Point). Usually a Hill Marker is used since the Hill Marker is very easy to see across the map and it has a very clear direction of orientation. (A crate or other movable object could be used, but then the location of the Invasion Respawn Zone can be moved during the game!) That direction identifies the direction of the Respawn Camera when the player switches to that Invasion Respawn Zone .
The respawning player can turn the Respawn Camera left or right or down, but not up. This allows the player to view what is at his feet, such as a spawned Power Weapon. For Power Weapons, some Respawn Cameras have a very good view or are directly over or in front of the Power Weapon spawn. In others, the Power Weapon is off to the side or down a platform, out of sight of a Respawn Camera.
By raising the Invasion Respawn Zone Marker vertically, the Respawn Camera is literally raised up to reveal areas of the map unobstructed by obstacles. Yet, when a player spawns, they spawn on the highest surface directly below and slightly behind the center of the Respawn Camera - they do not "fall" from the Respawn Zone Marker.
As an aside, you can position a Respawn Zone Marker over a wall. The respawning player can choose which side of the wall he wants to spawn on by looking over the wall in the other direction. Players spawn just behind the camera.
Usually, Invasion Respawn Zones are assigned to only one Fire Team, but there are exceptions. Invasion Respawn Marker set for all the Teams of one Species are typically used only where their vehicles spawn. Otherwise, there is only one case of a group Respawn Zone and that is found on Boneyard Tier 3 Defender side. In this case, there is one Respawn Zone positioned along the Core's path to help the Defenders head off a Core capture - to give them a half a chance. The alternative is that the Core could reach the point where the Defenders simply cannot stop it, and the rest of the Game Play reduces to a boring walk in the park.
Summary
Hill Markers are best for Invasion Respawn Zones, since they offer a clear indication of which direction their camera points.
The Invasion Respawn Zone Marker can be positioned above cover to allow its camera to see over the cover, while the player spawns behind the cover.
Group Respawn Zones can be used to view spawning vehicles and Power Weapons.