When you open iPhoto for the first time, you’re asked if you want iPhoto, or a different application, to open each time you connect a camera to your computer. You can change this preference any time.
To choose the application that opens:
Make sure no cameras are connected to your computer.
Choose iPhoto > Preferences, and then click General.
Choose an option from the “Connecting camera opens” pop-up menu.
iPhoto is an option. Another option is Image Capture, an application included with Mac OS X that you can use to transfer photos and video from your digital camera to your computer. Image Capture is useful if:
You want to transfer photos from your camera to your computer, but you don’t want to import them into the iPhoto or Aperture library.
You automate part of your photo-editing workflow with scripts that download and preprocess photos before you import them into iPhoto or Aperture.