How do I take a picture of the login screen? I've seen quite a number of login screen screenshots. I've tried Cmd + Shift + 3, but to no avail. How do I take a picture of the login screen or the boot screen of OS X?
You can SSH into another Mac and use screencapture in the shell.


Enable remote login in the sharing preferences on the other computer
ssh username@other_computers_ip
sudo screencapture ~/Desktop/screenshot.png