I wouldn't buy any old movies or TV shows on BR discs. The picture quality is the same as DVD since they did not use HD cameras during the filming. Most movies and TV shows within the past 2 years are HD but anything older... save your money and buy DVD.
Not true, not true at all. Most movies are shot on 35mm film. There are some that were shot on 70mm. 35mm is way, way higher in resolution in comparison to the DVD. 70mm is even better. So a movie shot on film in the 50s would look better on Blu-ray than it would on DVD.
In fact, the HD camcorders/cameras they use today is still not better than 35mm film cameras they use. Right now, shooting a movie on 35mm will still be higher in picture quality than you would get from a top of the line digital video camera like Sony/Panavision's Genesis. Some movies like Superman Returns were shot on Genesis. Casino Royale was partially shot on Genesis. It has been shown that there is still a long road for the digital video cameras to outperform the film cameras. The thing is, digital video camcorders are a great idea if you are on a budget and it can makes a movie looks great at a fraction of a cost. However, if they want to make a top-notch quality movie on a big budget, they usually go with film.
Do you think they use DVD at the theatres? No, they use film because if they were to use a DVD on a screen the size of 2 elephants or more, it would look like crap. They also use either a 2K or 4K (high resolution) DLP projector to show the movies digitally but if a film projector is set up properly, it would look better than any digital presentation. At many theatres, the projectionists don't know what they are doing so they end up making it look bad. Therefore, they will buy into the DLP projectors because they are already calibrated and set up to look stellar which they do.
A DVD is not the best presentation you can get in viewing an old movie. It is only a heavily compressed edition when compared to the movie on a film reel.
Don't believe me? Go see 2001: A Space Odyssey on Blu-ray. It's hard to believe how amazing this movie looks on Blu-ray. It looks brand new and a lot of scenes look like as if they were shot yesterday. It was shot on a 70mm film which gave it a very sharp and clean look. They did a great job on restoring the movie.
A lot of TV shows between the 70s and 90s were shot using analog video cameras so yes, they will be unable to upper them to 1080p. However, if they were to remaster some of the TV shows that were shot on film, they can. Seinfeld was shot on film and they did remaster it in high definition. They also remastered Star Trek, the original series in high definition since it was also shot on film.
A show like Full House cannot be because they were shot on analog video. That's a big difference from shooting on film.
A lot of people tend to make assumptions and this is something they often do. I see it all of the times and I have to correct them. Misinformation is usually bad when it comes to movies and TV shows. Nearly all movies are shot on 35mm and on some rare occasions, 70mm. Sometimes 16mm is used.
Film has no real resolution, only grains. Film are made up of grains and it depends on the quality of the film that you use. Hollywood tend to use decent and top-of-the-line film to shoot their movies on. So far, there are still no video formats available on the market that are better than film in the terms of picture quality.