There are quite a few external add-on lenses for smartphones out there. I haven't tried any except the Freewell 1.7X Telephoto which has received significant praise. I'm more interested in pushing the light gathering capability of the S23 Ultra for star photography. So I dropped some $ and got Freewell's case .. quite cool .. and 2 lenses .. the 1.7 Tele and the long range macro (not evaluated yet). The performance of the 1.7 tele, which is ONLY usable with the main X1 S23 Ultra camera doesn't disappoint. Sort of between the X1 and X3 S23 zooms but with more light. Most importantly, star field photos are quite good .. fairly sharp star images over the entire fov and solid no-wobble tight-alignment attachment to phone. The link below is my review with the details but here are 2 photos with the star photo (hopefully) instantly recognizable.
(I wouldn't specifically get this 1.7 tele lens for just the zoom capability but rather for the lens quality and light gathering capability. I really hope Samsung designs a lens like this, but designed to couple to EACH of the 3 main lenses as they obviously could achieve the best possible result with a matching case design comparable or better than Freewell's magnetic locking case.)
With and without 75mm long range macro
Some shots with Freewell's 75mm long range macro. Good if you like creative blur/focus. However, the macro capability of the S23 Ultra by itself is very good and you can get as close as ~ 30mm with the S23 UW 0.6X camera.
