At least, they tried.

Most films of this age, when released on DVD, don't bother with Extras, because there isn't anything. The cutting room floor has been cleared years ago. No one has Behind The Scenes guff and the suits in the office don't want to fork out real money to interview the old cast and crew - those they can find - to cobble together nicey-nicey reminiscences in a nostalgic atmosphere of bonhomie.

Capricorn One has home movies. Someone had a camera running during filming, first in the desert - abandoned garage sequence - and then in the studio on the fake Mars set. It's not great, it has to be said, and simply reinforces the general view that making a movie is a slow, achingly boring process. It's watching stuff like this that makes you admire actors even more. There is a scene with James Brolin lying on the ground, having sand sprinkled over his face and neck and then a live scorpion is enticed to walk across his cheek.

The filming is all over the place, hand held and undisciplined. Occasionally the screen goes green, as if it's packed up, but then comes back a minute later. You watch Brolin being made up to look sun blistered, before washing his face in the water tub. This takes forever. No one seems to know what they are doing, although Brolin looks so focused, you wonder if there is anyone there. Peter Hyams, the director, is dressed in what used to be called "groovy gear," tight pants, almost flared, leather cap, turtleneck, fashionable 'tach. He wants to be liked. He smiles a lot.

There is not much to say about these home movies, except don't bother. The What If.. Making Of featurette has all the actors, plus Hyams and a producer, giving sound bites about the film's concept, like on a promotional sales reel. It is embarrassing and, once again, you feel sorry for the actors.