according to the Beatles Examiner. The fan who shot the footage, Mary Ann Summers told WogBlog back then:
"I was 18 when I took it, and had bought the Super 8 camera specifically
for the concert. Yoko was in the 11th row, just across the aisle from
us, and seeing her take her seat confirmed the rumor Lennon would be
there was for real. When Lennon came on stage, we were standing on our
chairs, so the footage of him is fairly shaky, and maybe a minute in
length, if that. And it was taken from the 12th row orchestra, so there
were various heads I was shooting over while trying not to fall off my
seat. I clearly remember my friend yelling at me "the floor is shaking"
during the Lennon set."
The footage was posted on YouTube by Mary Ann, but has since been removed. Now it has been worked on and improved by Elton John's people and can only be seen at the singer's Million Dollar Piano show at Caesars Palace during the performance of "Empty Garden (Hey hey Johnny)", which Elton and his songwriting partner Bernie Taupin wrote after Lennon's tragic death.