If you are a photographer using anything but an iPhone for your work, chances are that the Photos app drives you nuts. I mean its aggressive nature to jump on any media or camera connected. Although you can disable this auto-start for cameras one by one, CF and SD cards are still an issue, as there’s no way to disable the auto-start for them on the user interface.
So here’s the trick: disable it globally. Open Terminal and copy & paste the following commands:
On OS X 10.10 (Yosemite):
defaults -currentHost write com.apple.ImageCapture2 HotPlugActionPath -string ""
defaults -currentHost write com.apple.ImageCapture2 LastHotPlugActionPath -string ""
On OS X 10.11 (El Capitan):
defaults -currentHost write com.apple.ImageCapture disableHotPlug -bool YES
You may need to log out and back on for the changes to take effect.