I found this old picture years ago, I called it a „natural stereo-view”. If you put it in, or under a stereo viewer ( in this case a French stereoscope for aerial photography ), you will get a three-dimensional picture of one “merged” twin. Our brain assimilates the two pictures as one and corrects irregularities automatically. Its not always necessary to have a stereo-camera to get stereo-pictures: once I took a picture of two red cars of the same model standing side by side. You can also take two identical houses, or two Coke bottles to get a “real” stereo image. I dont know if the term "natural stereo view" already exists, but finding or taking such pictures is fun.
Those stereo viewers and cards from the 19th century are still relatively easy to find in the U.S. The viewer used here was quite a bit different. Wer had one at one time and a number of the cards but they disappeared somewhere along our journey.
Looking at that wooden apparatus, I'm wondering how carefully the two photos need to be positioned relative to each other, in order to be viewed as a stereo image (without making a person dizzy!). I've never seen anything like that up-close.
Wayne, That type of stereo viewer is still known in the UK as a Holmes viewer. We had one at home when I was a small boy. I was fascinated.
It's posssible, with practice, to view a stereo card in 3D without using a viewer. You hold it in front of your face with the division between the pictures exactly in the centre between your eyes.
Then you deliberately focus your eyes on infinity (the well-known 'far away' daydreaming look) and move the card either towards your face or away from it untill you see three images, one left, one right and the centre one in 3D.
It took some practice when I was first shown how to do it, but I can do it very easily now. I can get a semi-stereo effect with Mik's picture of the twins, but it isn't easy because of the different hair styles and angles of the heads. One or the other twin keeps intruding in mono.
Just struck me. As viewing stereo cards is known as stereoscopy I suppose looking at an ordinary photograph could be called monoscopy??
I printed the "stereo" photo and cut it apart. I viewed it (them) on a stereoscope similar to the one that Wayne showed. They are not a stereo pair: The left image is higher than the right. The hair is different. The position of the hands is different. There are other differences as well. The fur piece has a left and a right side. But there are plenty of inexpensive old stereo pairs available at flea and antique markets and garage/boot sales.
Nevertheless it is a charming photo of what must be twins.
Last Edit: Mar 4, 2010 19:27:00 GMT -5 by mickeyobe
The two girls on the picture are not exactly horizontally placed, this is the reason why I used a “bridge” stereoscope ( you can easily adjust the picture at a horizontal level on the table ) It has also a variable eye base, which must be set as tight as it gets, because the distance of the “two” pictures is too close as in a stereo view taken with a stereo camera ( about 2cm missing ). It is working, believe me ! It is truly not a stereo pair, because biological cloning had not been invented in 1900 . I guess there is no 3D effect looking through a Holmes viewer inserting the picture in the holder. You may try to hold the photo manually and rotate it by ca. 5° . Stereo cards became quite rare here, 20 years ago they had been sold for cents, today they will sell for 5.- USD and more. Luckily I am not in urgent need to get some, I have two or three thousand in my collection ;D