playing with some manual touch-up techniques for phone photos, specifically using a black-to-white gradient overlay to fix vignetting. it works decently, but the camera effect is nonlinear and i haven't figured out how to make the gradient curve nonlinear yet, so it ends up over/undercompensating where they mismatch. the post-touch-up one looks good at a glance, but you can see some stars missing in a ring if you flip between them.
[edit:] it's kinda hard to pick out with how many stars are visible, but Cygnus is almost dead center in this shot.