The Eclipse Ray

August 21, 2017

In the absence of specialized equipment, a popular method of eclipse viewing is to create a makeshift camera obscura. The standard approach is to get a box, such as a shoebox, and create two holes on one side of the box: one of the holes must be just large enough to peer through, and the other hole must be made using something extremely small, such as a needle or pin. When light from an eclipse passes through the smaller hole, it forms an image of the sun on the inside of the box. Although this method works, the resulting image can be small, faint and difficult to see.

After brief experimentation using holes, lenses and mirrors, I came up with what is effectively a scaled up version of the camera obscura. My approach increases the size of an image hole from a pinhole to a 1.5 inch diameter opening, with a roughly proportional increase in distance from the image.

Unlike light passing through a tiny hole in a hand held shoebox, my device required light to strike a distant surface after passing through a large hole. In order to achieve this, I placed the hole directly over the surface of a mirror. In this way, the beam could be directed to a distant surface after passing through a hole: the street therefore became my 'shoebox', and the houses became its 'insides'.

Click on each image for a large view

Image hole on mirror

Eclipse 'ray'