John Greschak - A Simple Eidolumen Camera

A Simple Eidolumen Camera

by John Greschak

November 2, 2008

Introduction

This article describes a simple camera formed from a flatbed scanner and a glass marble that may be used to photograph eidolumens. (Note: The term eidolumen was introduced in the article Eidolumen: n. Light that is a Resemblance.)

Constructing the Camera

An eidolumen camera may be assembled from a flatbed scanner and a glass marble.

For this purpose, the scanner may be any flatbed scanner that consists of the following components: a cold cathode fluorescent lamp (CCFL); some number of convex mirrors, filters, and lenses; and a charge-coupled device (CCD) sensor.

Various types of glass marbles may be used. The characteristics (i.e. brightness, color, etc.) of the resulting photographs will depend upon the particular type of marble that is selected. Translucent marbles are especially useful for this purpose. In particular, clear marbles that have an Aurora Borealis (AB) coating yield interesting results. (An AB coating is a thin metallic finish.) Marbles that are cracked internally are quite useful as well. (One may crack a marble in this way by subjecting it to a rapid change in temperature.)

To form the camera, the glass marble is placed on the glass surface of the scanner. The camera is connected to a computer with a USB cable. It is operated with the computer using scanning software.

Photographing Eidolumens

Eidolumens may be photographed by taking pictures in a dark room. A high resolution (e.g. 4800 dpi) is suggested, though somewhat lower resolutions might yield interesting results as well. Photos may be cropped around the marble and saved as a file. (To avoid distortion that is associated with data compression in JPG files, photos may be saved as PNG files.) Upon examination of the photos, one might see numerous eidolumens within the perimeter of the marble. These will be easier to see when the photos are viewed (e.g. on a CRT monitor) in a relatively dark room. For more information on techniques for taking and viewing such photos, see On Inconspicuous Images within Images of Glass Marbles.

Some Eidolumen Photographs

Here are nine photographs taken with a simple eidolumen camera as described here. An HP Scanjet G4050 was used in combination with different types of marbles. All photos were taken at 4800 dpi.¹

Photo No.	Description of Marble
1	A clear marble with a relatively uniform AB coating for which the reflected light is white.
2	A clear marble with a relatively non-uniform AB coating for which the reflected light is white. It was oriented with the more heavily coated side on top.
3	A clear marble with an AB coating for which the reflected light is colored (i.e. the marble is iridescent). It is a shooter that is relatively out of round.
4	A translucent blue marble with an AB coating.
5	A translucent amber marble with an AB coating.
6	A clear marble with no AB coating. It is quite out of round with areas that are nearly flat.
7	A clear marble that is quite cracked internally.
8	A clear marble with numerous bubbles.
9	A marble (with no AB coating) that appears to be black and opaque but is actually translucent and colored .