What is Chromadepth® 3D?

You may have looked at a multi-colored printed image through what looks like clear glasses. The colors appear to be at different depth levels. Usually those that are “warm” such as red, orange and yellow are in front of “cold” colors such as blue, green-blue, etc. Although the glasses look clear, they are made of special material called diffraction grating. A diffraction grating is a piece of clear material with thousands of tiny grooves very closely spaced. A diffraction grating works in a very similar way to a prism in that when white light passes through it, it disperses, or breaks the light into its components, that is, into all the colors of the spectrum. White light that shines on the colored areas of the paper is reflected in different colors. That is because blue color absorbs all other colors and reflects back only the blue color, etc. When different colors reach a prism, those are bent at different angle. The angle depends on the wave length of the color that passes through. Rays of blue light are bent the most and those of red light are bent the least. See the drawing below:

When we look through the prisms (or through the special glasses that function in the same way as prisms) we must follow the angle at which the light is bent, and because the blue is bent more than the red color, our eyes must accommodate to look at a sharper angle. A sharper angle to the eyes means a closer object, and the opposite for an angle that is less sharp. Thus our eyes tell us: “look, since we have to focus at a sharper angle, this image must be in front of the other one.” Thus we fool the eyes to see depth where there is none.

While for the purpose of explaining how the glasses function we have compared them to simple prisms, the actual glasses used to view Chromadepth® 3D images are more complicated than that. First, part of the optics are reversed so that we can see the red in front of the blue colors, then they are constructed of a complex optical system that minimizes the chromatic aberration and other undesirable effects.

The glasses use a patented process owned by the American Paper Optics company. It is fun to design pictures composed of different shapes and colors and look at those through the glasses, like the two pictures here. However, you don’t need a special design, just about any multi-colored image will do the trick.

Look at the two pictures below with Chromadepth® 3D glasses, they show the effect well.
























Watch an interesting animation showing this phenomena in motion. You must use Chromadepth® 3D glasses for this!

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