Quote:
Originally Posted by benman94
When playing back a DVD or other digital video file (say with a storage resolution of 720 pixels by 480 pixels) back on a device that outputs a standard analog NTSC-M signal, are we not loosing some of the horizontal resolution?
If my arithmetic is correct, the highest possible horizontal resolution for analog NTSC video would be ~333 lines, and that is for luma. On one of our vintage color sets with a color trap, or a cheap B/W set with 2 or 3 IF stages, it should be ~250 to ~280 lines, given that we're no longer working with the full 4.2 MHz of luma bandwidth. The ~330 line limit should hold true for any set fed via an RF modulator, and also for composite video. A set with component would obviously not be limited in such a way.
Why store the video on a DVD with 720 horizontal pixels then? Why not 640? 560? Cutting the horizontal storage resolution would save, if not tremendously, on storage space. Given the storage limitations of a DVD, and the fact that it came out in the late 1990s, one has to wonder why they specified 720 horizontal pixels in the first place? I don't recall finding a tremendous number of sets from the 1990s with component video inputs.
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High end DVD setups in the 1990s did indeed use component video, and it made quite a visible difference in terms of picture quality. I think DVD video was designed not just for home use, but also for higher end setups using video projectors. My own home theatre is from 2000, and it has a Runco projector, which accepts component video. Switching between composite and component video makes a big difference in terms of picture quality. Also, don't forget the S-video connectors which were very very common on 1990s consumer gear. About any TV sold with a DVD player would have accepted S-video if not component, and this was sort of half way there.
DVD was the first consumer video format which had superior image quality to 16mm film, so it was also used with projectors in educational and institutional settings, where the highest possible resolution was very beneficial.