>>4440398
>The vertical and horizontal FOVs are different
True, but it's easy to account for that, see picrel. You can:
1. Compare across diagonal FoV, regardless of crop
2. Compare based on ratio A after cropping to match ratio B
3. Compare based on ratio B after cropping to match ratio A
> the rendering is different from using a less overcorrected lens
Different lenses be different, yes, that is equally true for any two 50mm on the same sensor though. In practice you would be unable to distinguish between two appropriately "equivalent" FoV shots.