How To Connect Two Projectors To One Laptop
You may want to connect two projectors to one laptop for presentations, gaming, and other purposes. The reasons are that the pixel density of projector screens often is lower than regular computer monitors.
Pros & Cons of connecting two projectors to one laptop
– To display the same screen on both projectors.
– To enlarge the image easily.
– To make a slide show with music at a big event (some school festivals).
– To make a video by using two cameras (or, three cameras) and connect them to two projectors for super-wide images.
– Most laptops have only one DVI or VGA output.
– Some projectors require scaling which can be painful depending on image quality.
Steps To Connect Two Projectors To One Laptop
Connecting two projectors to one laptop sounds like it should be fairly hard. Here’s a quick tutorial that covers how to get the job done using VNC – Virtual Network Computing. But the basic idea is the same for any OS, just different steps.
We will assume you have two computers on hand. One of them already has an LCD monitor connected. The second computer we will connect as a projector:
First step – On both computers install TightVNC and set up everything in advance:
On Computer #1 (the one with the LCD) I configured my first screen to have resolution 1400×1050 then chose clipboard sharing and added a password just because tightvncserver allows it.
Make sure the desktop manager for both computers is disabled – this means that you need to have multi-monitor support in your graphics card and be able to disable it from within the OS. The usual way of doing this can vary a bit depending on your hardware, so consult your manual on how to do this.
For those who are lazy here’s what I did: On my Intel machine (Centrino Duo) I ran “driconf” in command line mode as root and disabled “EXA” which is short for “Extended Accelerated Graphics Port”. You know you have found the right option if there are two settings: one for Primary Video Adapter (Intel Corporation Mobile 915GME Express Integrated Graphics Controller) and one for Secondary Video Adapter (VirtualBox Shared Screen).
Finally make sure your PC’s BIOS doesn’t have any video output options – or disable them if there are. This is a common setting in laptops, but you may need to check this step anyway.
On Computer #2 (the projector) create a new VNC user with password “vnc”, then run the command: sudo apt-get install tightvncserver
Next on both computers launch the TightVNC Server application from their respective System Tools menus, enter your vnc server settings and connect to each other using vnc://<your_ip> where <your_ip> is the IP of the computer that started the server.
When you finish these steps you should see the desktop of Computer #1 on Computer #2’s screen, in fullscreen and at 1400×1050 resolution. Just grab your mouse and start working – both computers are connected to each other as if they were wired together.
You can even share files, or run applications on your main computer but have them show up on your projector. The VNC protocol is also secure for those who care about such things.
Obviously one laptop will be slower than two, so depending how fast your Intel graphics are this may affect the refresh rate of the output a bit (but it should still be usable).
Finally note that I disabled an Xserver earlier – which means there’s no need to plug into a monitor before starting Tightvncserver on computer #2 – so long as you can access the internet from both computers, it works! 🙂
Good luck and hope this helps others to achieve similar results.
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