A Seventeenth Century Camera: Johann Zahn and the study of optics 

by Alexandra Caccamo Special Collections Librarian

Digitisation is an important part of our work in the library. It increases access to our collections and helps us make them available online to a greater number of people. With the development of our Digitisation Suite and the arrival of the scanner to the library, it is interesting to look at our collection for early descriptions of the camera. 

The Russell Library holds a number of books that deal with the study of optics. One such item is by Johann Zahn (1641-1707) Zahn was the canon of the Premonstratensian monastery of Oberzell near Würzburg. He had an interest in natural philosophy and published several works, with the most notable being ‘Oculus Artificialis Teledioptricus Sive Telescopium‘ or The Long Distance Artificial Eye or Telescope. This work was published in 1685 in Würzburg. 

Plate depicting Zhan’s design for a portable camera obscura

The book is a treatise on optical instruments and their uses. It describes magic lanterns, telescopes, microscopes and other projection types. Zahn also outlines and illustrates the first portable camera obscura. A camera obscura consists of an entire darkened room with a small hole at one end through which an image is projected. It should be noted that he was not the first to describe a camera-like device. The Han Chinese philosopher, Mozi (c. 470 – 291 BC) described the principle behind the camera obscura and detailed how light travels in straight lines from its source thus inverting an image when projected through a small hole. However, Zahn was the first to publish a design for a portable mirror-reflex camera, which you can see here. Although it is still relatively large, and perhaps not what we would think of as portable today, it was innovative at the time. This design did not become a reality until almost 140 years later. 

Plate showing how light travels in straight lines.

‘Oculus Artificialis Teledioptricus…’ has 190 pages. The title page is printed in black and red ink, with an additional richly engraved title page facing the printed title page. This engraving depicts an oculus artifci, literally artificial eye or a telescope. The book is illustrated throughout and contains 8 double-page tables, 30 engraved plates and numerous engraved and woodcut illustrations. Many of the plates are quite elaborate including one examining optics and the structure of the eye. 

Plate showing the structure of the eye.

There are also a number of plates which depict the refraction of light. 

Although, cameras have come a long way since the seventeenth century, we are still developing new ways of capturing images. In the New Year, we hope to be able to image, digitise and share more of our collections online. 

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