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7.7 Stereo photography 2137.7.1 Stereo photography with a single cameraWhat works for a chicken can work for us, too. It isn’t really necessary to usetwo cameras for creating stereo images. If the subject matter doesn’tmove, you can obtain good results by using a single camera: take the firstshot, move the camera a bit to the right, and take the second shot. Thismethod is particularly suitable for macro stereo photography. In macrophotography, the shift between the left and the right image must be quitesmall—so small that it’s impossible to mount two cameras side by sidewithout exceeding the optimal distance between the two lens centers.Shifting a single camera, however, sounds easier than it is. It can bequite hard to make both images register correctly, especially when shoot-ing hand-held. The SDM offers (just like the CHDK) the Edge Overlay as anaid:f First, switch on the Edge Overlay by clicking the ALT button and thenpressing the FUNC/SET button for a second. You should now see a no-tice such as “Allocated xxxxxx bytes”. Press ALT again to leave the mode.f Press the shutter button a first time. The Edge Overlay should appearnow in the form of bright yellow lines. Also, the message “frozen” isshown.f Move the camera a bit to the right, but not too much. Use the distancebetween your eyes as a guide and also see below. For macro work youcan choose a much smaller distance, and for landscape work you canexaggerate the 3D impression by choosing a larger distance.f Now register the camera so that the edges of the nearest subjectsmatch. The difference between the edges of the farthest objects (devia-tion) should not exceed two millimeters on the screen (assuming adisplay width of approximately two inches).f Take the second shot.f Now switch to Replay mode. Navigate to the first (left) image and half-press the shutter button3 to select it. Then navigate to the second (right)image and half-press the shutter button again. The display should nowshow a red/cyan overlay of both images (anaglyph). If you have yourred/cyan goggles with you, you can view the image in 3D right away.Under ALT > MENU > Stereo > Playback mode you can choose between amonochrome anaglyph, a color anaglyph, or a side-by-side pair.The main purpose of this display option is, however, to check theregistration of both images. If you want to magnify the anaglyph, youmust first zoom in on the left image, half-press the shutter button, then3 On the S2 IS, S3 IS, S5 IS, and A550, use FUNC/SET instead of the shutterbutton half-press. |
