From Wikipedia:

The Apollo 11 missing tapes refers to Apollo 11’s slow-scan television (SSTV) telecast recorded in its raw format on telemetry data tape during the time of the first Moonlanding in 1969. The recordings were discovered to be “missing” after a team of retired NASA employees and contractors tried to locate the tapes in the early 2000s.

The data tapes were recorded as a backup in case the live television broadcasts failed for any reason. In order to broadcast the SSTV transmission on standard television, NASA ground receiving stations performed real-time scan conversion to the NTSC television format. The moonwalk’s converted video signal was broadcast live around the world on July 21, 1969 (UTC). At the time, the NTSC broadcast was recorded on many videotapes and kinescope films: they were never missing.

…

Although the researchers never found the telemetry tapes they were looking for, they did discover the best visual quality NTSC videotapes as well as super 8 movie film taken of a video monitor in Australia, showing the SSTV transmission before it was converted. These visual elements were processed in 2009, as part of a NASA approved restoration project of the first Moonwalk. At a 2009 news conference in Washington, D.C., the research team released its findings regarding the tapes’ disappearance. They also partially released newly enhanced footage obtained during the search. Lowry Digital completed the full Moonwalk restoration project in late 2009.

Apollo 11 missing tapes (from Wikipedia) Apollo 11 HD Videos (NASA)