Sweden's most famous April Fool's Day hoax occurred on April 1, 1962. At the time, SVT (Sveriges Television) was the only television channel in Sweden, and it broadcast in black and white.
The station announced that their "technical expert," Kjell Stensson, was going to describe a process that would allow people to view color images on their existing black-and-white sets.
The broadcast cut to Stensson sitting in front of a television set in the studio. He began to explain how the process worked. His discussion was highly technical, going into details about the prismatic nature of light and the phenomenon of "double slit interference." But at last he arrived at the main point. Researchers, he said, had recently discovered that a fine-meshed screen placed in front of a black-and-white television screen would cause the light to bend in such a way that it would appear as if the image was in color.
Stensson told viewers they could experience the effect at home with the help of some simple, readily accessible materials. Nylon stockings, it turned out, were the perfect fabric to use as a fine-meshed screen. So all viewers had to do, Stensson said, was to cut open a pair of stockings and tape them over the screen of their television set. The image on the television should suddenly appear to be in color.
The original broadcast (in Swedish) — from the SVT archive
Stensson cautioned that the viewer would have to be seated at the correct distance from the screen in order to get the full effect. Also, it might be necessary to "move your head very carefully" back and forth, in order to align the color spectrum.
Thousands of viewers later admitted they had fallen for the hoax. Many Swedes today report that they remember their parents (their fathers in particular) rushing through the house trying to find nylon stockings to place over the TV set.
Announcer: We hope you have the implements you need for the color TV experiment handy: A nylon stocking, a pair of scissors and a roll of adhesive tape. Over to our technical expert, Kjell Stensson.
Kjell Stensson: As you probably know, there's a lot of interest in the problem of color television all over the world. Research is currently being carried out in America, the Soviet Union, Japan and other places. I found it remarkable when, about one month ago, a suggestion was unexpectedly presented to me how this problem could be solved, which had the advantage of extreme simplicity compared to the hi-tech solutions.
Like all great leaps of progress, it was based on very elementary ideas, and didn't demand more knowledge about optics and physics than what's taught in basic school. We all know that white light consists of a mixture of the whole spectrum, and white light can be split up by simply using a prism. We've seen this diagram in school. Put a prism in the way of a ray of white light, and the white light gets separated into all the colors of the spectrum, all the colors of the rainbow beginning with red, orange and so on, all the way down to violet. The term is color dispersion.
It's also possible to achieve color dispersion by other means, which I will show you in the next picture. Two slits are made in an opaque wall and light is shone through them. The holes then act as two separate light sources. Depending on the distance to the opposite wall, the different color components of the white light will reinforce or suppress each other, and this will cause an impression of color.
Now, this is two slits only, and the idea of this suggestion was to cover the TV screen with some kind of raster, a kind of grid composed of multiple slits. The man who suggested this, a resident of Bockstahus north of Landskrona, Pål Arne Utmeister, came up with the idea that a nylon stocking could be used, or very fine-meshed curtain cloth, which would simply be put over the screen, thus creating such a raster.
I have done precisely that with the monitor here in the studio, I've covered it with a stocking. That's why I asked you to have a nylon stocking, a scissors and a roll of tape handy. It's essential that it's fine-meshed. Should you try something larger - I've made an experiment with this athletic undershirt, and clearly the holes are too large for the effect to appear.
However, if you put it up (and if you don't have time to do it during this programme, you can do it later), you will see this picture of me suddenly appear in color.
Like I said earlier, the viewing distance is of utmost importance. You should experiment with moving closer and further away from the set to get the correct color impression. In order to assist you, we have prepared a calibration card. (Image: "White / red / yellow / green / blue / black")
Now move your head very carefully (the necessary movements are very small) and when this spectrum appears, you have found the correct position. If you're too far away, the red color may disappear, if you're too close, the green color may go away. The result could be disastrous, for instance our female announcers, who are beautiful blondes, may appear red-haired, which may be somewhat disconcerting for them.
This is still in a very preliminary phase. I've been in contact with the television industry, which needless to say is very enthusiastic about this. They will engineer a kind of frame with tightening screws that allows you to fine-tune the distance, and it will naturally be available in very pleasing designs.
If you now can see this color range — white, red, yellow, green, blue, black -- perhaps not in the absolutely correct nuances but approximately, you will enjoy the following little film immensely. It's a video color recording of different flowers, which I find to be a breathtaking symphony in colors.
We would appreciate hearing your views. Please write to us and let us know how this experiment turned out.
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