Dahua do a standard mounting base that could be secured to conduit. It's 20mm here in the UK, I'm not sure what size it is in imperial heathen land but it'll probably tell you in the specs for the American model of the base.
I also regularly see cameras mounted straight on to basket or tray if that's run at the right level, or if there's a suspended ceiling the tiles are fine to mount on as long as a wooden back board is fitted.
I have an open ceiling in my showroom and I want to drop them down from the trusses or joists. My open ceiling is spray-painted black so I was thinking an EMT conduit painted black with some sort of pendant mount on the back of the camera that can thread onto the EMT, and then I have a mount on the other end of the EMT that is clamped to the trusses. I have seen a commercial product like this but it costs more than the cameras and I don't even know if the pendant base would match up with the holes on the Dahua camera. Most of the bases I have seen that can be secured to conduit secure it from the side. I want something that will let me mount the conduit to the back of the base like this:
Or worst case scenario, you thread the conduit into a galvanised terminal box and make two new mounting holes in the base to mount it to the terminal box. They do make a ceiling pole themselves but it's probably 10 times the price of a length of conduit.