Famous Astrophotography Cameras

The Cameras used in Astrophotographer fall into two distinct types.

The first type or Astrograph is where the camera and telescope form a single integrated unit, and can typically only be used for photography.

The second type is a camera forming a separate unit independent of the telescope, that can be attached and removed from the optical tube assembly (OTA).

Each type has evolved over the last century and a half from at first simple units into what are now very sophisticated electronic computer controlled devices.

The Astrograph began life in the mid nineteenth century as a simple telescope with a light box attached to the end of the OTA containing a photographic plate. 

The most famous example of this early Astrograph is the Kew Photoheliograph which was used to take daily images of the Sun for twenty years from 1862-1882. It was designed by Warren De La Rue and constructed by Andrew Ross, following a suggestion from Sir John Herschel of the benefits of such an instrument.

In 1930 Bernhard Schmidt designed his Schmidtspiegel (now known as the Schmidt Camera). His invention has revolutionized astrophotography and telescope design. For the first time an optical system had been developed which had a wide field of view which remained sharp right to its edges. 

A number of Schmidt Cameras have been produced notably the 48" Oschin-Schmidt at Mount Palomar which came into service in 1948.

The Oschin Telescope was responsible for the discovery of 90377 Sedna on the 14th November 2003 and Eris, the "10th Planet" on 5th January 2005 from images taken on the 21st October 2003. The peculiar Type Ia supernova SN 2002cx was discovered with the Oschin telescope in May 2002.

Although George Ritchie and Henri Chretien had developed their own improved wide-flat field design earlier than Schmidt, it was expensive and difficult to test. It has only recently over the last ten years or so, begun to supersede Schmidt’s design at both the amateur and professional level; culminating in the launch of the Hubble Space Telescope in 1990.

The separate Camera developed much in line with advances in normal camera technology. 

At first it consisted of a simple photographic chassis complete with a photographic plate holder, a focusing mechanism and mechanical shutter release. A notable example of this was the one used by Loewy and Puiseux to take the images for their Photographic Atlas of the Moon.

In the last quarter of the 19th century a number of specialist cameras were developed, notably the ‘first webcam’ – the so called Revolver Photographique built in 1874 by Pierre Janssen to be used to take a ‘video’ of the transit of Venus that year. It was capable of taking 100 photographs per hours or 0.02 fps!

Over time photographic plates were replaced by plastic transparent film, first in black and white then in colour from the mid 1930s onwards.

The photographic chassis became more sophisticated gradually developing into modern camera bodies, complete with electronic shutter release, automatic focus and adjustable lenses. Such systems were either attached to the telescope for prime focus astrophotography or as standalone/piggyback astrophotography.

However, the use of film was almost entirely confined to amateur use, the large professional Observatories still continued to use Photographic Plates. This was because film was unable to obtain the wide field images often required in astronomical research.Large Format films were likely to distort and bend as a result they were not widely used in the professional astronomical community.

These plates required a considerable amount of preparation and in particular a complicated process of sensitization in the laboratory, prior to being used at the telescope. It was almost impossible to create two plates which reacted identically during a long exposure.

In 1969, all was to change forever with the invention by Willard Boyle and George Smith at AT & T Bell Laboratories of the Charge Coupled Device, better known as the CCD. By 1973 Fairchild Semiconductors had produced the first commercial CCD of 100x100 pixels. This was followed by a huge investment by the Sony Corporation which succeeded in producing mass produced CCD chips for its cameras and camcorders.

From the 1990s onwards specialist Astronomical CCD Cameras began to appear, but suffered from small array sizes resulting in image pixilation and high system noise. 

The use of Photographic Plates in professional Observatories began to be replaced by the CCD from the mid 1990s.

At the beginning of the 21st century Astronomical CCD Cameras produced by manufacturers such as Santa Barbara Instruments Group (SBIG) had much larger chip sizes with pixel arrays numbering in the 100’s of 1000s, thermo-electric Peltier coolers. These were however expensive and often too much for the average amateur.

Also at this time GOTO Telescope and Mount Technology became common as did image acquisition and processing software, all vital to creating a successful astrophotograph.

The first inexpensive Astronomical CCD Camera was introduced by Meade and had a 510x492 pixel array (250,000 pixels). This was followed up by later improved models. The Meade DSI has been instrumental in introducing many amateur astronomers to astrophotography. Inexpensive Astronomical Webcams with frame rates as high as 60fps also began to appear, which were ideally suited to Lunar and Planetary Imaging.

As of today (August 2009) Astronomical CCD Cameras with Pixel Arrays of up to 11 Mega Pixels are common, they often include a separate second Guide Chip, as well as both Thermo-Electric and Water Cooling. Their price is still too high for many amateurs.

Once hooked on Astrophotography, many progress to ever more expensive and sophisticated Astronomical CCDs produced by SBIG, Finger Lake Instruments and Starlight Express. 

The ordinary Digital SLR cameras also are popular with Astrophotographers. They have a number of advantages, being easy to use, provide wide fields of view and can be used for terrestrial photography. 

Also they do have a number of disadvantages resulting from being not specifically manufactured for astronomical use. In particular they suffer from high noise and cannot be cooled easily, as well as requiring a special IR Filter (to allow light at Hydrogen Alpha wavelength through – vital for Deep Space Objects such as Emission Nebulae).

The CCD and GOTO revolution makes it now possible for an amateur with modest equipment to take astronomical photographs of unbelievable high quality, as good as those produced fifty years ago by the largest telescopes in the world.

You can now have a ‘Palomar‘ in your backyard or on your balcony.

Kew Photoheliograph

'Revolver Photographique'

Modern Astronomical CCD

Image Camera Date Type Manufacturer Location Media Details
Bache Astrograph 1885 Photographic Plate Alvan Clark Boyden Observatory, SA Photographic Plate: Scale of 2cm = 1 degree More...
Bruce Astrograph 1904 Photographic Plate John Brashear Yerkes Observatory, USA 12"x12" & 8"x10" Glass Photographic Plate Chasses. More...
Crocker Astrograph 1892 Photographic Plate Charles Usener Lick Observatory, USA Collotype Photographic Plates; 1.81 degrees per inch. More...
Daguerreotype Camera 1839 Daguerreotype Various Universal Location Copper Plate Coated with Silver Iodide More...
Dallmeyer Photoheliograph 1873 Wet Plate John Henry Dallmeyer National Maritime Museum, Greenwich, England Photographic Plate Chassis More...
Digital Single Lens Reflex 1991 DSLR Various Universal Location CCD Chip Various Sizes More...

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