Doctor M said:
Sure, you'd expect some cropping. But my point is that the anamorphic and wide releases of Jungle Book actually have more left/right information than the 4x3 releases.
If the 4x3 version is all the animation fit to be seen, the widescreen should ONLY be less on the top and bottom.
Not necessarily. If you are framing at a particular AR, if you show more on the sides then you have to show more on the top and bottom. So a 4x3 transfer were to show as much on the sides as the widescreen ones, it would necessitate opening up the image that much more on the top and bottom, potentially revealing stuff we weren't intended to see (refer to the misframed Fox and the Hound Blu-ray screenshot, and the Great Mouse Detective framegrab from that recent 35mm auction).
And remember that in general, one framing has to be chosen for the entire transfer, or at least each reel, so if they are paying attention to the cel cutoffs and such, they would pick a framing that hides them in every shot. If one shot has an abrupt cel end at a certain frame height, the entire transfer has to be framed to cut off before that height, and so an equal amount of picture has to be sacrificed on the sides.
On the other hand, since a widescreen transfer mattes more on the top and bottom, they can afford to show more on the sides without revealing frame cheats on the top or bottom. This is all ideal circumstances, of course - if the technicians frame it too tight, we can get something like the 2002 Great Mouse Detective transfer where its 1.66:1 ratio cropped more on the sides than it opened up on the top and bottom.
We've seen plenty of transfers which are the "correct" AR but still a bit too tight (the Blu-ray of Alien, every transfer of Jurassic Park in the last 10+ years). And we've seen ones which are not properly centered as well (that Fox and the Hound Blu-ray, the original pressings of the Back to the Future Part II DVD where the entire transfer was framed too high). Transfer framing seems to be more of an art than a science.
A transfer showing all possible information without ever showing any of the garbage on the edges in any scene wouldn't necessarily be 4x3. It would probably end up being some oddball ratio (since there is usually more "garbage" on the top and bottom than on the sides). And if each individual shot were framed to show the maximum information without revealing flaws and cheats, the ratio would likely change from scene to scene.