What lenses were used on 2001: A Space Odyssey? - Quora

For the camera, they used a Panavision 70mm.

In terms of lenses, for all of the wide angle shots they used this Fairchild-Curtis custom fisheye:

The lens in action below. Look at how enormous that front element is in relation to the camera. This was necessary because 2001 was shot on 65mm film, which is twice as wide as standard 35mm film. The “T-AO” on the film magazine above the lens is for “Todd-AO.” The “AO” is for “American Optics.” Todd-AO was the format invented and used in the 1950s to shoot “Around The World In 80 Days.” It was owned by Mike Todd, then was inherited upon his death by his wife Elizabeth Taylor. This camera was also most likely used to film “Cleopatra.”

Here is another picture from the set, with Kubrick looking on. You can see the entire Panavision setup, but it's hard to see the lens in this photo:

2001 was shot with a 5-perf 65mm (2.20:1) negative using spherical lenses, which is the format originally called Todd-AO and then Super Panavision (when Panavision built cameras & lenses for the format). "2001" has "Cinerama" in the credits, but technically to SHOOT in "Cinerama" means using three 35mm 6-perf cameras built into a single-unit with their three 27mm lenses holding a 146 degree field of view, with an aspect ratio of approx. 2.60:1.