He could zoom in on the astronauts for a closeup or even adjust the lens opening to compensate for the moon's harsh lighting conditions.
From the time.com
One of the final images found on Kouzaris'digital camera shows a closeup of Kouzaris, slightly grizzled, staring into the lens.
From the heraldtribune.com
Then at another performance, with a telephoto lens, he made the closeup of Miss Singleton's face and the filmed background in order to complete his final montage.
From the time.com
The crew used a 50 mm lens to make it easier for the effects team to dissolve the closeup shots with the other elements.