encontrou a resposta para como parar iPhoto de abrir aqui: link
Open Image Capture and go to the Preferences menu (under the Image Capture menu item). Under the General tab, change the option for “When a camera is connected…” to “No Application” instead of “iPhoto”.
This means you’ll have to manually start iPhoto when you connect your digital camera, but you won’t have to CLOSE iPhoto every time you plug in your iPhone (which, for me, is a heck of a lot more often than plugging in a camera!)