Apple introduced simple–and really, really good–Screen Sharing starting back in OS 10.5 (Leopard), but most people don’t seem to know about it. We’ve got multiple computers (Mac laptops, a desktop, one PC, an iPad, iPods, iPhones), and I’ve found Screen Sharing to be a great way to help me manage and use all of these systems.
Everything I’m talking about here on a Mac can be set up on a PC as well, using VNC or other screen sharing, but it’s not as easy as on the Mac.
[Actually, there may be something built into Vista and beyond for this, but I don't spend much time on Windows lately.]
Be a couch potato!
Sure, you could do everything on any computer on your network from your comfy chair. You know, the red one you inherited from your dad, who was a consummate purchaser of the Ultimate Comfortable Chair, and which is now sitting in the corner of your bedroom, by the windows with the best view, and in front of the stereo. No, wait, are we talking about my chair, or yours? Any way, grab some Cheetos (they turn your keys a lovely orange hue) and let’s talk.
Yeah, but why bother?
Well, I can snoop on what you’re doing, right? No, not actually. When I log into a machine and see its screen, the computer I’m attached to displays an icon in the menu bar to show that someone else is viewing that screen. It’s not completely anonymous.
I use screen sharing for a couple of types of tasks.
Most importantly, I have a Mac Mini that I’ve set up as a whole-house iTunes server, as described in this post. That Mini is attached to a big screen TV (hey, does this make you want to break into my house? I also have a whole-house remotely-monitored alarm system with, uh, punishment spikes and flame throwers and a high-intensity electric field, but that’s a subject for a different post). I use screen sharing so that I can easily access that iTunes server without needing to start up the big TV.
So screen sharing lets me start music, stop music, add movies and music to my library, categorize new music, etc. from any screen in the house.
Note: new iPods and iPhones also let me control my iTunes server, using Apple’s free “Remote” application. Great stuff, and it generally does the trick. But sometimes I just want to access the computer directly, so screen sharing lets me do that.
I can also use Screen Sharing to access the various computers in the house and restart, update or shut them down. Sometimes this is easier than wandering around, since any computer in my network that’s turned on (i.e. not asleep) is broadcasting that fact. So I can be on my laptop and maintain, shut down, etc. any other computer.
Apple’s screen sharing is also fast (on a high-speed WiFi-N network), so I can actually do work on my desktop computer by directing it from my laptop.
Why would I bother? Well, did I mention the comfy red chair? Also, sometimes I want to get work done on that desktop computer (like sorting photos or video) from the bedroom so I can be with M in the evening. As long as what I’m doing doesn’t require sound or a lot of heavy UI interaction (no scrubbing back and forth across video, for instance) I can do it just fine remotely.
And starting with Lion (10.7) I can even put the Screen Sharing window into full screen, which makes it look like I’m fully ‘on’ that remote computer.
Ok, how do I set it up?
On the Mac that you want to share *from*, go to the Apple menu>System Preferences… dialog, and then goto the Sharing group.
Give your computer a memorable and simple name, in the Computer Name edit field.
Select the checkbox next to “Screen sharing”. You should now see a green dot next to “Screen Sharing: On,” indicating that it’s now active.
On the right of the dialog, under “Allow Access For:” you can either choose Administrators, or All Users, or add specific users (if you’ve set up multiple user accounts on that computer). I choose “Administrators” since I’ve got admin access with all of my own user accounts.
Great. Now you’re screen sharing from that Mac. Note that this only (normally) works on your local network, so you’re not going to be able to access your screen from your neighbor’s house, or anywhere else but your place. It shouldn’t be a security concern.
How do I log in?
On any other Mac that’s using Snow Leopard or later, open any folder or Finder window. On the left of that Finder window, you should see several categories of items: Favorites, Shared, Devices and so forth. The computer that you enabled for Screen Sharing should be listed there under the SHARED category. Click it.
Now you should see a “Share Screen…” button. Click that.
You’re presented with a “Log In” dialog. You can use your username and password (rather, the username and password of a user on that remote Macintosh–presumably if you have multiple Macs though, you’ve set them up with the same username and password for “you” on each one). Check “Remember password” so you won’t have to log in next time you want to see the screen of that remote computer.
If the username and password corresponds to one of the users that you specified when you set up Sharing (above), or has Administrator privileges if you chose that setting, then you should now see the screen of the remote Mac. Huzzah! You’re in control. You can copy and paste, move stuff around, etc. Just as if you were sitting in front of that Mac. To stop screen sharing, just close the Screen Sharing window. OR, right-click (or Control-click) the Screen Sharing app in your Mac’s Dock (the Mac you’re actually using) and choose Quit.
Creating a Log-In Screen Sharing Shortcut
Now that you’ve logged in once, you can create a simple Shortcut in your dock so you don’t have to hunt around again in order to log into that particular machine. Close Screen Sharing so you’re once again looking at your Mac.
Do this (Lion): go to the Finder by clicking on the Finder icon in your Dock.
Press and hold the Option key on your keyboard, and from the Finder menu, choose Go>Library. [Why the Option key? Because in Lion, Apple hides the Library folder so people like us won't go in there and screw stuff up.]
The Library folder for your user account (the account you’re currently logged into) now opens. In the Library folder, open the Application Support folder, then open the Screen Sharing folder.
Inside Screen Sharing, you’ll see little VNC settings files corresponding to each computer you’ve logged into. You can drag one or more of these to your Dock (on the right, where documents are stored). Now you’ve got a saved login and can log into that remote Mac with a single click!
Screen Sharing from an iPhone, iPod or iPad
There are many screen sharing apps for iOS devices. I’ve tried several (both free and paid), and my current favorite is Remoter VNC. It’s easy to set up, nicely designed, and full featured. Using this, I can use my iPad to fully control my Macs remotely. Works great.
If you want to use a Mac Mini as a headless (no monitor) server, and use Screen Sharing to control it, you may run into times when screen sharing fails and you need to be able to see the Mac directly, and plug in a keyboard and mouse. Example: computer crash, or some unknown screen sharing failure. This happens to me occasionally, and when it does I try to get the Mini to display on my television. Normally this works, though sometimes it’ll fail to sync to the TV (which is at a much lower resolution than I normally use) and I have to haul over a monitor. C’est la vie.
Last caveat: if you’re still having trouble screen sharing, look at your Firewall settings. Make sure you haven’t chosen a restrictive setting that’s preventing screen sharing from working.