Title graphic for the exhibit: From Eyeballs to Electrons page title:

boxes of plates

By the first decade of the twentieth century, the photographic plate had become the dominant detector in observational astronomy. New telescopes were conceived as cameras and designed for photography, older ones adapted for taking pictures. No large professional observatory was without a photographic capability, and astronomers became proficient darkroom technicians.

In the years that followed, millions of plates were exposed at observatories all over the world, tens of thousands of them by Lick astronomers using a long succession of cameras and spectrographs. The principal telescopes of Lick's early years—the 36-inch refractor, its 12-inch cousin, and the Crossley reflector—had been built during the last hurrah of visual observing, but were now mainly used for photography. The major additions of later years—the 20-inch dual astrograph and the Shane 120-inch reflector—were photographic telescopes from the outset, their eyepieces serving only to acquire targets and guide exposures.

Photography's long reign lasted until the arrival of digital imaging in the early 1980s. However, it was increasingly sharing the stage with a variety of electronic detectors that, at Lick, had begun appearing as early as the 1910s. Part II of From Eyeballs to Electrons will tell the story of their development and, finally, of the digital revolution in astronomy.

Note: When discussing the history of astronomy after the discovery of celestial radio waves in the early 1930s, it becomes necesssary to make the distinction between optical observations and those made at other wavelengths. From Eyeballs to Electrons is concerned with the detectors used in optical astronomy. Learn more.

Click on the thumbnails below for more on astrophotography at Lick Observatroy in the twentieth century. twin astrograph Dual Astrograph Planetary camera Astrometric camera 120-inch plates plate vault shelves Plate Vault