Mac OS X has some excellent screenshot tools available, both built-in and third-party. These can be very helpful, in the case that you need to quickly put a guide together to help someone troubleshoot his/her Mac or similar. One thing that the default screen capture tool can’t do is to take a screenshot of the login screen.
Luckily, the procedure is not that difficult. It just requires a bit of patience, and two Macs. Both of them need to be connected to the same Wi-Fi, that’s all. We’ve detailed the entire process below, so check it out.
To get started, you’ll need two Macs. In this case, my “first Mac” is the one I want to take the screenshot of, and the “second Mac” is the one I’ll be using to take the screenshot.
Note: The “second Mac” doesn’t have to be a Mac. It can be any computer (Windows or Linux) that supports the SSH protocol. You can also run it from your Android phone, though you will need to have a rooted phone and install a Terminal app.
Enable Remote Login on your First Mac
The first step you need to take is to enable Remote login on your first Mac. Make sure both Macs are connected to the same Wi-Fi network.
Note: We won’t recommend following this guide while using a public Wi-Fi network, as remote logging into your other Mac over an open network may compromise your data. Proceed at your own risk.
1. Open System Preferences on your first Mac.
2. Click on “Sharing.”
3. Click on the Lock icon and authorize yourself in the opening window to allow changes.
4. In the left hand checkbox window, enable the “Remote Login” option.
5. In the Remote Login section, you’ll see a string of text saying “To log in to this computer remotely, type “ssh …………………..”
Save this ssh string of text somewhere safe for quick access later.
6. Log out of your Mac to get back to the login screen.
Remote Login From Your Second Mac
Now, follow the steps below on your second Mac:
1. Open Terminal on your Mac, either by using Spotlight or by navigating to “Applications -> Utilities -> Terminal”.
2. Type in the ssh string of text you noted down earlier. The complete command, after its written, will look something like this:
3. Press Enter, and your second Mac should remotely log in to your first Mac. Once successfully logged in, your second Mac should show your first Mac’s public name in Terminal, as shown below:
Now simply enter in the following two commands one by one into Terminal on your second Mac:
Basically, what this command does is tell your second Mac to log access to the account’s Desktop on your first Mac.
Enter the second command:
sudo screencapture -tjpeg loginwindow.jpeg
This command will set the screenshot type to jpeg, and the file name to “loginwindow.jpeg”.
You can replace JPEG with any picture format you’d like to take a screenshot in. Once the command is entered, you should hear the “Camera clicking” sound on your first Mac.
That’s it. Now, when you log in into your first Mac, you’ll see a file on your Desktop named “LoginWindow.jpeg”, as shown below:
This is the screenshot you took.
Note: If you repeatedly need to take screenshots of your Mac’s login screen, be sure to first save each screenshot somewhere else before taking the next one, else your Mac will automatically overwrite the previous screenshot when you take a new one.
If you need to take screenshots of your Mac’s login screen, you can do so easily, by remote logging into your Mac and following the steps above. Just be sure to use this guide carefully, because if this “remote-logging” feature gets into the wrong hands, it could be potentially dangerous, for you and your ever-so-precious data.
Be sure to let us know of any issues or problems in the comments section below.