OT - TV Video effect

It doesn't matter what photo. Its age or whether it was taken on film or digital aren't important. Once it exists as pixels (which will require scanning if it's a film photo) then all sorts of manipulation techniques become available, such as drawing a lassoo line around a foreground object and cutting it from the background. Having done that, if it is slightly enlarged relative to the background, so it covers the "hole" it came from, leaving a border around it, then the foreground object can be panned relative to the background to create an illusion of parallax. Obviously the greater the amount of movement required, the greater the overlap needs to be - or else you need to draw in missing background, either manually by cloning from nearby background or automatically by content-aware "invention" of pixels.

Why is any of that more difficult with an old photo than a new one?

Actually they could use a completely different photo for the background if they have one that looks right.

The process you describe is what was done in the TV programmes I saw. What I was querying was the suggestion from Jim K that the hole could be filled in automatically, so not needing the foreground to cover it. That process is easy but the results may vary. I refer you to John Rumm's posting of 30/03/19 17:22.

Pass

Ken Morse then.