An Easy Way of Producing Stereo Images

Various of our animals have also been photographed using the SEM for stereo images. The images are in greys, but they can be used to produce nice stereos. An easy way for presentation without special lenses, just putting red-green glasses on, is explained below. 

Making stereo images from bw stereo photographs, e.g. SEM images

Here you can learn to produce stereos in just a few minutes:

All you need for this easy way of having nice stereo images on your website is a graphics program, stereo images and red-green spectacles. I have ordered some from a company on the Web, but you may get them in toy shops too. Note that TV spectacles turned out to be useless because the colours are not suitable and you will not get a good stereo effect.

 Start

To start with, you can download these two stereo pairs of images that don't fit too well, but are good for practising (the animal is called Dala peilertae and is a small Orsten crustacean, the picture depicts part of the trunk from ventral). Double-click on them to receive the larger versions and copy them to your computer.

Procedure
  1. Open one of the images in Adobe Photoshop or another image processing program. All further instructions refer to Photoshop.
  2. Cut left and right ones out and store as individual files. If not done already, turn each image into RGB mode to make them coloured = 24 bit (3X8 bit). Jpegs should be so already, but in either case it is necessary to have the three colour channels Red, Green and Blue.
  3. Use the tone correction window (Apple L on a Mac, most likely a similar short cut on a PC).
  4. Start with the left image, which will become the red one, underlying the right = green one (the left is the one that equals the left page when you open a book, while the right angles against it = ca. 6-8 degrees depending on the object).
  5. Choose the channel scrollbar and wipe out green and blue by chosing the lower horizonal bar (not the one below the histogram). Just pull it to zero and you will see the effect.
  6. Then choose the right image and, similarly, make it bluegreen by wiping out red. That's most of the jobs done already.
  7. Pull green on top of red (will appear in an overlaying layer in Photoshop).
  8. Select the layer for the green image (by opening the layer window) and change to about 46 % opacity (100% is fully visible, 0% is invisible, and anything in between are degrees of transparency).
  9. Now you can see both images. If they are too dark, use the tone correction again for each layer and adjust light and grey levels to you wishes.
  10. Lastly take your spectacles (green to the right) and - while having the green layer still active - use the cursors to adjust the overlying until the stereo is fine.

After you have received some experience, you may choose a little different mode: first you blacken the background on each image, so having a nicer view of the object. Then enlarge the area of the future red = left image and black the surrounding area too, which helps when the overlying the green image.

After all is done you can just cut the image down to a suitable size either in the PS file or the final tiff or jpeg (both require that you reduce the image to a single layer!). That's it. The first try (quick and dirty) should not take more that 5 minutes.

Have fun, and it would be great to see your results once or any other response to improve this recipe, Dieter

Example images

Select from this set of thumbnails and look at 500,000,000 years old fossils in 3D. All you need are spectacles with red and green glasses (green to the right; TV glasses are less useful since their red is too dark and green to light).

   

   

1) Middle Cambrian waterbear, ventral view - 2) early and 3) late lava of the branchiopod eucrustacean Rehbachiella kinnekullensisMüller, 1983 – 4) 1st larva of the thecostracan maxillopod eucrustacean Bredocaris admirabilis Müller, 1983, a form related to the extant barnacles (Cirripedia) – 5) anterior view of the head of the supposed adult of Bredocaris admirabilis – 6) trunk leg of the early maxillopod eucrustacean Dala peilertae Müller, 1983 – 7) stereo image of the oldest crustacean, a phosphatocopine baby from the Lower Cambrian of Comley, Shropshire, UK, first published by Siveter, Williams and Walossek in Science (2001) 293: 479-481 (comment by Fortey on p. 438) and recently named Klausmuelleria salopensis Siveter, Waloszek & Williams, 2003 after the discoverer of the Orsten-3D-fossils, Klaus Müller from Bonn in Siveter et al. (2003) – 8) earliest larva (head larva) of the stem-lineage crustacean Martinssonia elongata Müller & Walossek, 1986