Forward Unto Dawn glitch
From Halopedia, the Halo wiki
By exploiting this glitch you can get a better look at the Dawn in theater.
Walkthrough
In the Level [The Ark when Forward Unto Dawn arrives and starts unloading its hogs and scorpions you can get a closer look at it by going into theater and then going into floating camera mode and positioning the camera under forward unto dawns cargo bay with your back to the end of the plateau then go backwards until you are stopped by an invisible barrier now press LB to go down and keep going down until you are on the lower ground at a certain point the barrier ends now go backwards as far as you can and voila you are outside the barrier now you are free to take a closer look at the beautifull Forward Unto Dawn.