Hi everyone, Yesterday I discovered that when I use the dummy battery with the Canon 50d and I try to take a photo the camera turns off at the exact moment it raises the mirror and remains with the it stuck in a raised position, then I reconnect the battery and the mirror lowers again. There are no problems capturing photos when the camera is in live view mode because in this case it only has to activate the shutter. I tried connecting the dummy battery to various 5v power banks and the transformed voltage is 8.42v, the one the camera receives, so there shouldn't be any problems but still this happens. Perhaps more than not providing enough current something strange happens and I don't understand if it's the software side, however it's just a curiosity to understand since fortunately I was able to take photos anyway keeping the mirror always raised with the live view.
The fault that you describe is exactly what you will get if your power supply has not got sufficient current capability. The proper dummy battery kit (Canon ACK-E6) for the 50D has an AC adaptor with an output of 8v 3A so a 5V power bank is definitely not suitable. I have found that various aftermarket dummy battery kits are just not capable of giving reliable results and the only one that works every time is the genuine Canon one.
