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What is the rating of the transformer? I don't have a spare camera but I can buy all the parts online.
Network transfer speed depends on multiple variables - Network Router Speed if you're using wireless - otherwise yout network switch speed, Server AND client Processor Speed, Ethernet Card Speed on both as well. All of which are lacking in power on an RPI for large file transfer. I'm using it for document hosting however
And storage device speed too which means either the speed of the SD card or the speed of the USB port on the RPI