Movie created in Full HD, then created a DVD and only SD quality, why?

I made a 2-hour movie with VEGAS and rendered it in Full HD (about 12 hours).

Since I like to burn it several times to DVD (with homemade (chapter) menu, etc.), I have now created a DVD in a folder on my PC.

I realize that the resolution is only 20% of HD, but I say the picture on the laptop is so bad and no comparison to the original Full HD video.

Is the difference on TV just as bad or is it not so noticeable because you're sitting further away?

It annoys me only because I have rendered 12 hours in Full HD and in SD it would have taken just 4 hours and now I just can't burn the resolution.

Just a hint: if you have a video, then render it - as you did - as HD video. However, do not burn directly to a DVD, but as an mp4 file (without loss of quality). With the finished rendered file, you can then do what you want (without always having to re-render).

So if you burn a DVD, the resolution is just 720x576 (SD) with an aspect ratio of 4: 3 or 16: 9. Is set for a DVD so that every player can read a DVD. You can't shake it.

If you want to enjoy Full HD on TV, then you have to burn a Bluray. Is the same (with menus) as a DVD, but you need a Bluray burner (and blanks). Bluray supports this high resolution.

Alternative: You render your movie as Divx AVI with Full HD resolution and burn it (as a data DVD), because most DVD players can play AVI - or you can put the file on a stick if your TV has a USB Socket and the format can play directly. Disadvantage: no menu.

Is the difference on TV just as bad

Yes.

The problem should be less the much lower resolution, but the length of the film.

DVD has in comparison to the BD synonymous significantly worse compression format (MPEG-2 instead of MPEG-4 or H.264 / AVC or even its successor H.265 / HEVC) while significantly less space (especially in the 4.7 GB of single-layer DVD5, which is designed for - optimistic estimated - 1h game time).

But the stronger the compression (due to the space on the disk and the ability of the codec), the worse the picture. This is the basic feature of (lossy!) MPEG compression.

Conclusion: Take for SD as a codec AVC and another version in HD with HEVC as MKV files. For very old devices, if necessary. Another XviD / MPEG-4 as an AVI file. And if that breaks the 4.7GB of the DVD, then take a two-ply DVD9.

But just without menus, only as a data DVD. For video DVDs with menu necessarily require the totally outdated MPEG-2 format.

Disk with AVI / MKV files can DVD player, but more so Bluray player - but from USB flash drive / hard disk in the meantime also TVs themselves - for a long time play - stop without menu.

If you exist on a menu, then burn a Bluray Disc! If the movie gets small enough (with HEVC!), Then you can also try burning the BD structure to a DVD disc. This also some BD players are clear, DVD players of course not…