The astronomers working at the Lick were often amateur scientists without formal education in either astronomy or optics, whose interest in photography and observation led them to the study of astronomy. They were learning about astronomy while trying to keep up with and improve optic and photographic technologies. Additionally, photographing the night sky itself was quite labor-intensive. Because the earth rotates, the observer had to carefully guide the telescope throughout the night in order to create an unblurred image of the object under observation. This was difficult to accomplish, especially given the length of exposure time required to capture the light of distant bodies, and astronomers often felt that the resulting images were not sharp enough representations of the object they had observed. We have in this archive only a few of the thousands of images created by Lick astronomers, as many were rejected. In an early reflection on the merits of astrophotography, one page of which is displayed here, Charles Perrine discusses the difficulty of guiding the telescope and the loss of structural detail that could occur in the process. Following comets was also tricky, and their trails often appeared "ragged," according to Edward Barnard.
Astronomers and technicians at the Lick quickly made progress in developing technologies to automate the guiding process, resulting in clearer and sharper images. The Lick sent these images to photogravure companies around the country, seeking out the most skilled photographic technicians to create faithful duplicates of those successful images that they had worked so carefully to create. Yet even the best images were often difficult for the printers to reproduce. Most of the images produced at the Lick were recorded on glass plates coated with photosensitive chemicals, measuring 3.25" by 4.25". As you can see with the plates displayed here, the object under observation often measured only millimeters in diameter on the plate. The printer was to transfer this image to a copper plate in order to make a print, which involved a long, complicated series of chemical processes. Accordingly, it was often difficult to carry the exact resolution and sharpness of the original image over to the copper plates.
Astronomers could not know what these distant, often invisible objects actually looked like; they were working within certain ideas about what they should look like and how to best represent them to the public. Yet their letters to the photogravure companies had many complaints--loss of light or structural detail, the lack of "snappiness" or contrast, the "thinness," or lack of depth or "blackness," of the sky behind the object. Their complaints were often aesthetic in nature and even involved inventing new aesthetic categories like "snappiness" to describe how a cosmic body should appear. The Lick's directors often required the printers to try again in order to blacken the background or bring out the faint structure of nebulae, yet they then would worry that the prints were too retouched and therefore not truly objective pieces of data.
What, then, is an "objective" representation of a galaxy or a nebula? How did the Lick astronomers negotiate the objective representation of the cosmos through aesthetic concerns? How is the reality of the cosmos--then as now--a matter of aesthetic standards and conventions?
These images and documents tell us how difficult it was for astronomers to create these early images of the cosmos, speaking to a certain intensity of labor on the part of the individual astronomer, but obscuring the labor of the technicians that would assist him or her in the process. Additionally, they also archive another story about how these aesthetic concerns impacted the labor of the printers in meeting the expectations of the Lick's directors.
To see more images of glass plates and a greater selection of letters exchanged between Lick directors and printing companies, see our digital exhibit.
N.B.: Our research in this area is greatly indebted to the work of Alexander Pang.