Video didn't exist as such in his lifetime.
He may have been filmed but I have not heard of it before.

You could look in the media section of Into The Wardrobe website.

I checked Into the Wardrobe and only found pictures of him in the "media" section.
If you search "CS Lewis video" you normally get documentaries.
I was wondering if he or someone in his household would have made home videos... but my brother suggested that ol' Jack might not have been quite the type to have new-fangled video cameras about the house. I mean, we're talking about the guy who preferred horses to cars. Seriously.

I'll try to find out for you, but I suspect that your brother is right in this. Even a 'Box Brownie' camera was pretty good technology in the 40s.

Did you check out the audio parts?

http://cslewis.drzeus.net/multimedia/

Ah yes, some of those were included in the radio recordings I found earlier. Good to hear Jack's voice- I'm just a bit disappointed that no actual video of him seems to exist.

It seems he may have been filmed on an old cine camera by a visitor once, but I assume that it has not survived all those years.

Do you know who might have filmed said video?

No, I doubt it could now be traced. It would be on fashioned film (the kind that is filmed on hand held home movie camera), and it probably perished over time. The person who mentioned it in something I read, said they didn't remember who had the camera, and that the film was probably no longer in existence.
I think that's the end of that. But you can watch several good presentations of Jack Lewis by excellent actors. The BBC TV film of Shadowlands (1980s) starring Joss Ackland, and the movie of the same name (about 1990) starring Anthony Hopkins, give a good idea of his character, even though some of the story is invented.