If you’ve ever spent ages composing a shot of a breathtaking landscape, only to be disappointed at how poorly the photograph represents the majesty of the scene, you’ll understand how marked a difference there is between what the human eye can see and what even the cleverest piece of digital gadgetry can represent.
Our brains use a variety of clues to calculate how close an object is when we view a scene. Perspective is preserved in photography, but depth is not, resulting in photos that look flat.
Because we have two eyes, we see the world from two slightly different viewpoints. Our brain combines the two images to give a perception of depth. In 3D photography, this extra element is put back into the mix, and the result is a true awareness of depth.
In the following workshop, we’ll show you how to create your own 3D images, as well as how to use your digital camera to create genuine ‘jump out of the page’ 3D photos.
The main trick with 3D photography is to take two photographs of the same scene from two viewpoints, one slightly to the right of the other – this is known as a ‘stereo pair’. But just capturing a pair of photos isn’t enough.
The other vital ingredient is a method of viewing the stereo pair so that your left eye sees only the left image and your right eye sees only the right image. There are lots of ways of doing this and the two we’ve chosen here have one very important factor in common – they don’t require expensive hardware or software.
Nevertheless, the results can be very impressive. Stereo photography dates back to the Victorian era but, thanks to digital techniques, is now more accessible than ever.
To prepare our stereo images for ‘free viewing’ we’ve used Corel Photo-Paint X3. This is bundled with CorelDraw X3; earlier versions can be picked up more cheaply. And you’ll be able to achieve the same results with almost any image-editing package.
To generate an anaglyph you’ll need the free Anaglyph Maker.
1. The easiest way to obtain a stereo pair is to take two photos, moving the viewfinder from your left to right eye between exposures. Stand with your feet slightly apart so you don’t wobble. Both photos will have been taken from the same height – provided you haven’t composed them in the LCD.
2. You’ll get far better results using a slide bracket mounted on a tripod, however. This ensures that both shots were taken with the camera facing in exactly the same direction. You can easily make one using two pieces of wood, glued and screwed together as shown above, and a tripod-mounting socket attached to the bottom.
3. Attach the slide bracket to a tripod, making sure it’s horizontal. Put your camera on the bracket at the lefthand side, ensuring it touches the rear support. Take a shot and slide it 70mm to the right, again making sure it remains in contact with the rear support. Now take a second shot.
4. A slide bracket will give excellent results only if the scene is stationary. A universal solution is to get hold of two identical cameras and mount them side-by-side using a home-made bracket. Be sure the settings are the same for both and use a remote control so that both shots are taken at exactly the same time.
5. Open the lefthand image in your chosen image editor (we’ve used Corel Photo-Paint X3). Select Paper Size from the Image menu then, in the Paper Size dialog box, select Center Left from the Placement pull-down menu and Pixels. Enter a value in the New Width box that’s double its original value before clicking ok.
6. Adjust the zoom level so that your image fits on the screen. Select Import from the File menu and choose your righthand image before clicking Import. Click into the blank, righthand portion of the screen to drop the second image there. Now drag it so it exactly fills the empty righthand side of the onscreen image.
7. Zoom out so that the combined image is just a few tens of millimetres wide. Using the free-viewing technique described below, try to view the stereo pair in 3D. If you can’t see the image, check that both images are correctly positioned. Once you can see the scene in 3D, move on to the next step.
8. You’ll probably want to make prints of your stereo pairs. Remember that the larger the image, the harder it will be to free view it in 3D. Unless you use a stereoscope, you can’t just print at any size as you would with an ordinary photograph. Make a few test prints at various sizes and try them out on your friends.
9. If you find free viewing difficult, try an anaglyph. Just about anyone can view in 3D using special glasses with coloured lenses. Install Anaglyph Maker, then click Load Left Image and browse to it. Open the righthand image in the same way by clicking Load Right Image.
10. Depending on the type of 3D viewing glasses you have, select either the Anaglyph Gray (Red-Cyan), Anaglyph Red-Green, or Anaglyph Red-Blue button before clicking Make 3D Image. A version of your photo with odd colours and fringes around objects will appear in the preview area.
11. If the left and right images aren’t correctly aligned vertically, use the U, D, 5U or 5D buttons to move the right image up or down by one or five pixels with respect to the left image. Also try the L, R, 5L and 5R buttons, which affect how far forward or back various objects appear.
12. To appreciate your completed 3D picture in all its glory you really need to view it in fullscreen mode – do so by clicking Full Screen. Pressing Esc returns you to AnaMaker’s normal viewing mode. If you aren’t entirely happy with the image, go back to step 11 and fine-tune it.
13. Mono anaglyphs will work with any photos but, provided your images don’t contain highly saturated red or cyan objects, you can also make anaglyphs in colour. For this you need to use red-cyan glasses. Simply repeat steps 10, 11 (if necessary) and 12, but select the Anaglyph Color (Red-Cyan) button in Step 10.
14. To save the anaglyph click Save 3D Image. Enter a filename and save the file in BMP format as a 3D image. Note that BMP is the preferred file format as Jpeg compression artefacts might affect the perception of 3D.