The transparent monitor illusion is created by using a picture of the area behind your monitor as your desktop wallpaper. The trick is in getting the picture's angle and area exactly right so that any features, such as cables, that cross over the frame of the monitor line up with the picture.
Materials needed:
- Digital camera (or a film camera and a scanner I guess)
- Tripod (or a lot of patience and a very steady hand)
- Basic picture editing software (nothing fancy)
First remove your computer's monitor from its usual location. Leave any cables, wires, USB hubs, or other features alone, they will help the illusion. It is important not to disturb them when moving or replacing your monitor so they will line up with the final picture when you're finished.
Next set the digital camera up on the tripod. Choose a location that is close enough to the monitor that you will get a good shot, but make sure it's not in the way when you're doing the rest of this. The tripod must remain in exactly the same place until you're done. You will be taking three pictures all from exactly the same angle and distance.
Now take a picture of the area your monitor usually sits in.
Replace your monitor and take a second picture, this time with your monitor there. Do not move the tripod yet.
Download (or scan) your pictures into the computer. Start up your image editing software and crop the picture of your missing monitor so that it only includes the area inside the monitor's frame. Use the second picture for reference. Optionally, you can add some kind of effect to the pictures, to make your monitor look semi-transparent, or like it's made of frosted glass. You will not need to correct the color, if it doesn't quite match it just adds to the illusion.
Now set the cropped picture as your desktop background. Get a bunch of icons on your desktop and make sure your taskbar (Windows) or dock (Mac) is showing. Open up a small window or two, the calculator application works well, to get something on the monitor. Don't use a large window or it will cover too much of your effect. We just want to confirm that this is an actively used computer.
Take a third picture. This picture is the one you will show people, with the desktop background image of the area behind your monitor. This illusion only works if the angle all three pictures are taken from is exactly the same. Unfortunately this means that the illusion also doesn't work well in real life, because the viewer would have to be at exactly the right angle and distance.
Note that your monitor's power and signal cables will obviously not be available for the first picture. Make sure that they are either completely hidden behind the monitor, or that they do not cross inside the monitor's frame except at the point they plug in. They could potentially ruin the illusion.
This illusion looks best when there is a lot of clutter behind the monitor, and especially if the clutter crosses out of the monitor's frame. With several cables, toys, features on the wall such as windows, and other objects on all sides of the monitor's frame, the effect can be stunning.
Note that this illusion doesn't have to be done straight-on, but it's probably easiest to get the images to line up that way. You can try doing this from different angles as well, as long as it's the same angle for all three pictures you take.
I didn't invent this technique. If you search Google for "transparent monitor" you can find several examples and sets of instructions.