I have an EOS 750D and simple reversing ring. There is no problem with capturing photos using the viewfinder. I have to use M mode and set everything manually.
But when I use live view (or try to capture video) I can only see a black screen. When in video mode, there is a message: "Ensure the lens is mounted..." Then I can capture video, but it is only a black screen with sound.
Is there a simple way to fool the mount that there is lens attached, or do I have to buy a more sophisticated set? What pins of the EF mount shall be connected?