A Gallery of Roberts' Images

Most observers are aware of the fact that the visual appearance of deep sky objects does not really match up to the way they look in photographs. We spend a lot of time searching for visual “landmarks” which will help us to see as much as we can of the magnificent structure revealed in even the simplest photos. The eye just doesn’t see things the way that film does.

In days past, we didn’t worry about this, because the visual image was the only one we had. Before 1900 deep sky photographs didn’t exist. Astronomy books featured elaborate drawings of galaxies and clusters.

The first astrophotographs were made shortly after Louis Daguerre introduced his Daguerrotype process in 1837. The “film” was slow, so only the Sun, Moon, and perhaps a few bright stars could be imaged. Faster film became available with the wet plate process, and longer exposures of celestial objects became possible. However, wet plates tended to dry out before much of an image could be built up.

Towards the end of the Nineteenth Century, dry plates were pioneered by George Eastman in the United States and the Ilford firm in England. One of the first to recognize the advantages of the new emulsion for astrophotography was Isaac Roberts (1829-1904), a wealthy amateur in Liverpool.

Roberts, a man of humble birth, apprenticed himself to a firm of mechanical engineers. He supplemented this training by attending night school. After much diligent work and study he established himself as one of the region’s most prominent engineers. During his years of study, he took courses in “natural philosophy” and found himself fascinated by the heavens. When at last money came his way, he was able to purchase a 7” telescope and establish a small observatory of his own.

Being by nature an experimenter, Roberts soon applied himself to the task of photographing the stars. His early efforts were probably no better than the efforts of other pioneer astrophotographers. However, Roberts was a man of vision. He was one of the first to realize the promise of the new dry plates. He thought that by making exposures of many hours duration, views of deep sky objects superior to any in existence could be produced. This he did.

Roberts ordered a 20” photographic reflector from the firm of Howard Grubb, England’s premier telescope makers. He met with such resounding success that the attention of professional astronomers was turned back to reflectors. These telescopes had suffered from nearly 75 years of neglect.

His first long exposure of the Andromeda Nebula revealed that that object was really a spiral nebula, much like M51. This was totally unexpected! His photos of other nebulae and clusters were equally revealing.

In his long exposures, Roberts found what we today take for granted. He was the first to reveal the “true” form of the nebulae and clusters. He changed astronomy forever by being the first to show us what these elusive objects really look like.