- Choose Apple () menu > System Preferences.
- Choose View > Energy Saver.
- Adjust the slider for "Put the computer to sleep when it is inactive for" to "Never" or a long enough interval to avoid sleep during a photo shoot session.
Aperture: Avoid putting the computer to sleep while shooting tethered
It's a good idea to avoid putting your computer to sleep while shooting tethered in Aperture or Image Capture. If the computer does go to sleep during a tethered session, your camera may no longer be detected, and it may be necessary to quit and reopen the application, unplug the camera and reconnect it. To adjust the sleep settings for your Mac: