Comment on Apollo 11 Conspiracy Theories by jfb.
You’re thinking of Apollo 17, not Apollo 11; there is no external footage of Eagle’s ascent.
The footage you’re talking about was captured by the television camera mounted on the lunar rover, which was controlled by technicians on Earth. To capture Challenger’s ascent, the technician in Houston tilted the camera manually; there was no automatic tracking. Despite training and practice, it still turned out to be a bit of a lucky shot, since the technician had to start the tilt about a second before the actual liftoff to account for the signal delay.