Prevent Automatic Opening of Photos in OS X
When you plug in your iPhone, iPad, or any other photo SD card, Photos love to open. We showed you how to disable this on a per- device basis , but if you prefer a more comprehensive approach, the terminal command is your best bet.
All you need to do is go to Terminal (Applications> Utilities) and enter this command:
default -currentHost write com.apple.ImageCapture disableHotPlug -bool true
With this, the photos will no longer open on their own, no matter what device you connect.
Stop Auto Opening Photos | Default – Record