How late to have photographer stay

Our photographers stayed until an hour or two before the party ended

Ours will be there for 9 hours from start to finish.

I think it depends on your timeline. I would have them stay through all of the reception events and then an hour of dancing. You really don’t need them there for the entire getting ready process, that takes hours. A few getting ready shots is usually enough for most people.

Whoops! Didn't mean to send that reply just yet. Our photographers stayed until 2 hours before the party ended and got a lot of great dancing pictures. We had them present while we got ready as well. It was definitely important to us to have our photographers capture candid moments and it was about 9-10 hours total (we had unlimited time with them.
Not sure what time your party ends but right before people get super rowdy or 2 hours before might be good, but also depends on what events or activities you might have other than dancing

If you're not doing a send off at the end of your reception I think it's ok for them to leave at 9

We opened the dance floor at 8 p.m. and our reception went until 11 p.m. Our photographer left shortly after 8 p.m. after we did our cake cutting and first dance. We got several pictures of people dancing. We also had a videographer who stayed until 9 p.m. and included lots of video of people dancing.

We also have our photographer with an assistant for 10 hours. They are leaving at 10pm, starting at noon. Our ceremony starts at 5pm, reception starts at 6pm and goes until 11pm. As long as you're not doing a send off you will be fine!

Our photographers will stay til the end of the reception because I don't want "getting ready" shots. I have them for 8 hours, so 2-10pm. They will come and start detail shots, then getting the dress on, surprising my bridesmaids with my dress, then separate bridal party pics. Normally I don't see photographers stay til the very end but I don't want/don't need them arriving any earlier than 2pm due to our timeline. I honestly wouldn't be offended if they wanted to leave earlier than the end of the reception, but I doubt they are like that.

We have our photographers for 10hrs. Our ceremony starts at 445pm and ends at 11pm. They are coming from 1pm to 11pm. They are going to start with the basic shots (getting ready, flowers, rings, dress those things). Then we are doing a first look and all of our family/ BP pictures before the ceremony. Then they will be there for ceremony and all of the reception. They are also doing sunset pictures with us and night shots with us. So they wont just be taking random pictures of drunks lol.