DIY Anaglyph 3D

Anaglyph 3D images have an illusion of depth if you look at them with 3D glasses. The trick is that there are two images overlaid on one another. One, the blue or cyan image, is invisible to the right eye but appears in its full contrast to the left eye. The other, which is red, is invisible to the left eye but shows up for the right eye.

They're easy enough to make. Here's how.

Since these instructions were written in December 2000, they assume that you'll be using the graphics program I was using at the time: Photoshop 5. Using the method with more recent versions of Photoshop would be similar. It would also be possible with other programs. Experimentation is key.

Take the Photos

Take a photograph of your intended subject. Step to the side and take another. The larger the step, the greater the spatial separation. Step too far, though, and you won't be able to get the images to mate up. Getting this right may take some practice, but as a rule of thumb you should take larger steps for subjects that are farther away.

Make sure to remember whether you took a step to the right or left; it's much easier than trying to sort it out after you've got the pictures on your screen.

Put them together

Get the photographs into Photoshop. This is easy if you have a digital camera, but scanned prints work fine.

Paste both photos into one file. Add a layer which is full up with cyan and another which is full up with red. These are the fully saturated colours which look like white to one eye of the 3D glasses and black to the other. If you want to just enter values, these are #00FFFF and #FF0000.

Group the cyan layer with the lefthand image and the red layer with the righthand image. Set the Blend Mode on the colour layers to Screen and on the photographs to Multiply. Center one of the two photographs, and move the other one until it is more or less lined up with the first.

Now put on the 3D glasses. Drag one of the photographs around until the you no longer see a double image. The picture should now look like it has depth.

Since the two photographs won't have exactly the same field of view, you'll need to crop off the edges.

Troubleshooting

Several things can go wrong. If you took too wide a step, the images will never line up. If you took too small a step, there won't be any appreciable depth.

Saving the image as a JPG with too much compression can destroy the effect. JPG artefacts that can barely be seen under normal circumstances can cause the two images to bleed together, making them both appear to both eyes.

Sometimes the spirits of the third dimension frown on your efforts.

Going Beyond

Once you get the basics down, try experimenting. I'm still learning about this stuff myself. You can try making anaglyphs out of ordinary pictures, but it's much easier if you start with a pair of photographs. The results can be nifty, however, like this desktop background:

I will probably post more pictures here as the mood strikes me, but you know everything you need to know to go and do it yourself. If you do make anything cool, drop me a line.

©2000 by P.D. Magnus.