Just did 50 with no luck. 50 different pokemon, all different species, 1 shot each, looked at each photo, looked around on map between pokemon... nothing.

Got nothing on day 1 either and did maybe 70 batches of 10 photos that day, so, nothing in 70 sessions. On day 2 though I got it in my first six sessions. Day 3 now, nothing in about seventy sessions (the fifty single-shot sessions I just did plus about another twenty sessions before that that were different batch sizes - 3, 10, 20). (FWIW I restarted the app before doing the fifty single-shot sessions.)

I think some accounts are flagged as “no” or “unlucky” and are doomed that day, and that Niantic doesn’t realize this is happening. There’s such a dichotomy in what people are reporting. My guess is that probability of Smeargle is supposed to be about 1 in 20 or whatever for the first photo, but that quite a few accounts are glitching out on that first photo, maybe on what qualifies as the start of a session, or on whether Smeargle shows visibly & spawns visibly on the map - it’s like the game thinks that account caught Smeargle already that day.