Panama Pacific International Exposition

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Viewing the Stereographs

About Anaglyphs

There are many ways to view 3-D imagery. All involve getting two pictures taken from separate viewpoints into your two eyes. Your brain fuses the two images into a single three-dimensional view. In their original format, the stereographs of this set are broken into left and right eye images. Each image is viewed by its respective eye through a magnifying lens.

Antique stereo viewer

Anaglyph glassesWith black and white protographs one can combine the two pictures into one. The key here is to color the two images with complementary colors (red and cyan, for instance) and then view the image through a pair of glasses that have the same complementary filters. Red and cyan are said to be complementary because a red filter will not let through cyan light and a cyan filter will not allow through any red light. The red and cyan pictures are overlapped. The viewer, looking through the red/cyan glasses will see different images in each eye and fuse them into a 3-D image. These complementary images are called "anaglyphs." { - GR. anaglyphe work in low relief, f. aná ANA- (up) + glúphein (carve)}. Anaglyphs work well for black and white photographs and with either print or computer screens.

Another way to view 3-D is to project each image on a screen with crossed polarizers and then view the image with similarly crossed polarized glasses. This cannot be used on a normal computer screen. With computers one can blink between two images on the screen and then wear special glasses that alternately shutter one eye then the other in syncronization with the blinking images.

How do I make 3-D glasses?

Making anaglyph glasses is pretty simple. As discussed above, all you need are two colored filters that are complementary colors. Typical anaglyphs have you put the red filter on the left eye and the cyan filter on the right eye. You can get these filters from any theatrical supply company (look in the Yellow Pages under 'theatrical supply'). We recommend Roscolux #26-Light Red and #77-Green Blue. This filter material is available in 20"x24" sheets and costs about $6.50 per sheet. Obviously you can make over one hundred pairs with your two sheets! Cut out cardboard eyeglass frames and tape the filters over the eye holes. If you need a template for the glasses, click here. Simple!

Where do I get glasses?

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