Have you been wondering what is the difference between projection modes in Lightroom panorama mode? Well today is your lucky day, here's your answer:
Spherical projection tries to aligns and transform the photos as if they were all plastered onto the inside of a sphere. This projection mode is tends to work best for very wide or multi-row panoramas and 360 panoramas.
Cylindrical projection projects the panorama as if it were placed on the inside of a cylinder. As such this mode works very well with very wide panoramas. Important to note here that it tries to keep vertical lines straight.
Perspective projection projects the panorama as though it were mapped on a flat surface. In this mode straight lines are kept straight so this mode works well for for architectural photography. You will find that if your panorama is super wide this may not work well with this mode as excessive distortion at the edges of the resulting panorama will occur.
This video explains the system well:
Video by Julianne Kost