2.35:1 Widescreen in 720x480 DVD?

[blaz]

How do they cram a 2.35:1 Widescreen movie into a 720x480 pixel frame of an NTSC DVD?

I understand how they fit a 4:3 and a 16:9 movie by stretching or compressing the pixels using the formula: SAR x PAR = DAR per frame (or Storage Ratio times Pixel Ratio equals Display Ratio), so:
4:3 >>>> (720/480) x 0.8889 = 4/3 = 1.333
16:9 >>>> (720/480) x 1.186 = 16/9 = 1.779

And I initially thought that they would stretch the pixels even more for 2.35:1 movies, but it looks like they have the same aspect ratios as 16:9 movies; but as they are letterboxed down to 363 lines from 480, the "effective" SAR and DAR change:
2.35:1 >>>> (720/363) x 1.186 = 2.352

Does this mean that (480-363) = 117 lines per frame are wasted? Just painted black and ignored? Can't be; a 2.35:1 movie needs greater resolution, not less ...

So what am I missing? Maybe higher video bitrates? ... ?

[JoeShrubbery]

Just painted black and ignored?

This. Yes.

[smok3]

your not missing anything, that's the way it is.
what bitrates had to do with cropping?

[blaz]

what bitrates had to do with cropping?

Well nothing, I guess.

And I guess that the black letterboxes don't take up that much of the video bit space on the dvd, because of the mpeg-2 compression scheme. Surely not 117/480 = 24%, I hope.

But even so, that's a great loss of resolution per frame. Especially since the 2.35:1 movies are typically those filmed with 70mm film. Not sure if I wouldn't prefer Pan&Scan, depending upon the movie ....

Anyway, now there's Blu-ray.

[um3k]

The funny thing is, Blu-Ray uses black bars as well...