HDTV: Television of the future, but not the past

Curtis recently wrote:

As the world moves to HDTV and 16:9 widescreen displays, people will still want to watch older programs– reruns of Star Trek, for example, which were created for 4:3 displays. Why not use the blank space on the sides of the screen to display ads?

Interesting idea, but it reminded me of something I’ve wondered about every since I first read the HDTV draft standard published by ATSC five years ago: Why are the high-definition resolutions (e.g., 720p and 1080i) not available in the 4:3 formats, and what will that mean for archival content?

I understand that widescreen is the Television of the Future, and I suspect that the reason that HDTV is widescreen-only was to encourage the switch to widescreen by both set manufacturers and content providers (i.e., networks and studios). The 4:3 “square” aspect ratio has long been considered inferior, and Hollywood has been trying to get us to use widescreen TVs for years. It doesn’t appear to have worked; I notice that consumer electronics stores are happily selling 4:3 HDTVs, although I admit I don’t know what they do when presented with actual HDTV (hence 16:9) content; I imagine they letterbox it, although they might have a zoom mode that chops off the sides.

But besides new content, there’s plenty of old 4:3 television episodes and movies that are ripe for high-definition conversion. Curtis’s example, Star Trek, was filmed and edited on 35mm film, and might benefit from an HD version (actually, it might not; it was shot for television, and adding extra detail might reveal that the costumes, props, sets and makeup was never intended to be seen that close up). But there’s no good way to broadcast it on HDTV without windowboxing—adding black bars to the sides—or cutting off the top and bottom. Which is, I guess, fine if you have a widescreen TV, but if you have a 4:3 HDTV (as mentioned above), what you end up with is a black box around an image that only takes up two-thirds of your TV. Even if you zoom in, you’ve lost a third of the resolution HDTV promises. It just doesn’t seem right.