Ben Affleck -- Wedding Ring Off ... Then Wedding Ring Back On (Photos)

Ben Affleck was out in Atlanta with his wedding ring back on -- days after announcing his split from Jennifer Garner, and being photographed without it.

Ben had a daddy day out with oldest daughter Violet -- hitting up a bunch of museums -- and flashing his wedding band. Jennifer and the kids are in Atlanta while she shoots a movie, and we knew he was flying in to hang with the kids ... but the ring is surprising.

Affleck was not wearing it earlier this week when he was solo in L.A.

But you can chill on the possible reconciliation rumors. As we've reported ... Ben and Jen intend to keep the divorce civil, and share custody of their 3 children -- and we're told the ring is on simply to smooth the transition for them.