We are trying to build multiple Photobooths next to each other, which are equipped with a tablet that has a UI to select and upload certain photos in a folder. Right now we use canon 700d/750d (which are at this point roundabout 7-10years old) with flashair cards to take the pictures and transfer them to the tablet where they can be selected and uploaded. The problem is: the lag and the delay. Most of the time the pictures are nearly as fast on the tablet as you can shoot (we don't shoot RAW for some reason) but every once in a while it starts to lag and lack connection... like 20-30 min. or more...
That's the reason why I've put my question up here. Most modern cameras are able to push selected photos to an android device nearby, but I couldn't find any that can do that automatically. At least not the low-end or middle class cameras we have. I've seen that the canon 5DMKIV seems to be able to auto upload pictures to an FTP server or a specific device on the network.