I'm still confused when reading about the differences between these two formats.
-Is the film you're recording onto the same size regardless of what you're using.
-For both formats you're essentially getting the same shot, but you just get to that 2.35:1 framing in a different way, right? With Super35 you shoot essentially a square image and crop it, whereas with anamorphic you get that cropped image automatically.
Why would someone would shoot anamorphic when super35 allows you to re-frame your shot in post. With anamorphic you seem to be locked into that framing.
Is there some benefit to anamorphic I'm missing? Are you actually getting more picture than you do with Super35?
35mm anamorphic uses the full height of the 4-perf 35mm negative for picture and the slightly less-wide Academy (sound) width, whereas Super-35 uses the full width compared to a sound aperture (we're not talking much, 24mm instead of 22mm) but only uses about 2.5-perfs worth of height for a 2.40 image compared to anamorphic (Super-35 only uses about 10.5mm worth vertically for the 2.40 image versus 18.5mm for anamorphic). So anamorphic uses almost twice as much negative real estate for a 2.40 image, and thus has less grain in the image if the same film stock is used.
There is also some improvement in detail recorded because of the larger negative area though offset by the fact that the anamorphic lenses aren't as sharp as many spherical lenses, especially at wide apertures. This is an old diagram I drew back when the conversion from Super-35 to anamorphic was done in an optical printer:
35mm anamorphic photography generally has less depth of field compared to Super-35 because the focal lengths used are different, since an anamorphic lens sees twice as much horizontally as the same focal length in spherical, you tend to use a longer focal length to get the same 2.40 composition as compared to Super-35, let's say a 40mm anamorphic lens would create a similar 2.40 view as a 24mm spherical lens in Super-35 cropped vertically to 2.40 (it's not exactly a 2X conversion because of the slightly different widths of the negative.)
Personally as someone who loves to compose
a frame through a camera, I'm not so fond of the idea of reframing in post, which is one reason I like anamorphic, the frame you shoot is the frame that gets shown to everyone in the theater. I've shot a couple of Super-35 movies and honestly there wasn't much reframing in post anyway -- the main advantage in those cases in choosing Super-35 was that it made the pan-and-scan home video versions easier (because I could go back to the taller used area of the negative), and it was easier to shoot in low light levels with spherical lenses. Anamorphic takes more work but it pays off in big shots, especially outdoors.
Finer grain and the lack of a conversion step is the main advantage of anamorphic, but now that everyone goes through a D.I. the conversion is the same anyway, and people seem to like grain these days, and the stocks are less grainy than they used to be -- so these days, more people are likely to shoot anamorphic for the unique optical artifacts and flares than for extra picture quality. But many producers don't want to budget for shooting 4-perf anymore and would rather you shoot 3-perf Super-35 (or digitally).
If anything you have it backwards, with a scope (anamorphic) 35mm print, the image area is square-ish (1.20 : 1) but has a 2X horizontal compression which is expanded by the anamorphic projector lens, so if you shoot with anamorphic lenses, you already squeeze the 2.40 image into that 1.20 square area.
With Super-35, you compose within a 2.40 rectangle in the taller negative and crop to that area to make the 35mm scope print version.
Of course, digital projection these days just uses a spherical projection lens and shows a 2.40 frame anyway, so Super-35 gets cropped to 2.40 but it doesn't necessarily have to get squeezed unless being recorded out to film for a release print.