American TV airs at 60 interlaced fields per second (60i), whereas Region 2 DVDs, like we get in the UK, have video at 50 interlaced fields per second (50i) or 25 frames per second (25 fps).
Films are shot at 24 fps, and I know about the pull down process for showing a film on American TV -- converting it to 30 fps by duplicating frames.
But what about American shows, essentially 30 fps, on 25 fps DVDs? I'm wondering especially about Seinfeld, which I've been watching on Region 2 (25 fps) DVDs for years. I've never seen any of the jerkiness you'd expect from a conversion from 30 fps to 25 fps.
I believe Seinfeld was shot on film. Was it shot at 24 fps and then pulled down for its original TV run, so that the 25 fps DVD versions are actually much closer to what was shot than the 30 fps American TV broadcasts?
If so, how widely is this technique used? I've seen quite a few American TV shows on Region 2 DVDs and I've never noticed jerkiness (that I can remember), but I don't think they can all have been shot on film at 24 fps.